JPS6023359B2 - electronic musical instruments - Google Patents

Description

[Detailed Description of the Invention] This invention generates a fundamental wave (fundamental tone) and its harmonic components (overtones) corresponding to the pitch of the pressed key, and multiplies the fundamental wave and harmonic components by amplitude coefficients corresponding to each. The present invention relates to an electronic musical instrument using a harmonic synthesis method that forms musical tones by synthesizing the multiplied values of multipliers, and particularly to an electronic musical instrument that can freely produce anharmonic musical tones with a simple configuration.

A. Description of the Prior Art An electronic musical instrument using the harmonic synthesis method obtains a musical tone by sequentially calculating the amplitude values at successive sample points of a musical sound waveform based on the equation {1-. be.

(q=1, 2,...) Here, Xo(qR)... Waveform amplitude value at each sample point of the musical sound waveform.

R・・・・・・・・・・・・・・・Frequency of generated musical tone (
A numerical value (hereinafter referred to as a frequency number) proportional to the pitch (pitch).

n・・・・・・・・・・・・Represents the order of harmonic components including the fundamental wave, n=1 is the fundamental wave (fundamental tone), n=2 is the second harmonic (second overtone) , n=3 is the third harmonic (third overtone)... , . ．． corresponds to

Cn・・・・・・・・・・・・Amplitude coefficient (Fourier coefficient) for harmonic components of each order.

N・・・・・・・・・・・・Number of sequential sample points of one musical tone waveform at the highest frequency of the generated musical tone W・・・・・・
......Total number of harmonics to be synthesized at sequential sample points.

There is a relationship of W=N/2.

In addition, in the following explanation, harmonics includes the fundamental wave, and the fundamental wave is Let it be the first harmonic.

An electronic musical instrument based on this harmonic synthesis method is configured as shown in FIG. 1, for example.

In the figure, 1 is a key switch circuit provided in the keyboard section, which has a key switch corresponding to each key of the keyboard section. When a certain key is pressed, the corresponding key switch operates. It is configured to output a signal with a logical value of "1" to the output line. This key switch circuit 1 has a built-in single-note priority circuit, so that when two or more key switches operate at the same time, a "1" signal is output only to the output line corresponding to the key switch with the highest priority. It has become. The output line corresponding to each key switch of the key switch circuit 1 is connected to the input side of a frequency number memory 2 in which a frequency number R corresponding to the pitch of each key is stored. Then, the frequency number R corresponding to the pitch of the key is read out from the frequency number memory 2, addressed by the output of the key switch circuit 1. on the other hand,
The clock oscillator 3 outputs a wide clock pulse with a constant period, and this clock pulse tC is frequency-divided by W in the counter 4, so that the calculation interval timing signal becomes .

In this case, "W" is the total number of harmonics to be synthesized. For example, when synthesizing up to the first Hahajima harmonic wave, "W=1
6". The calculation interval timing signal tx created in this way is supplied to the gate 5. This gate 5 opens every time the calculation interval timing signal 戊 is combined, and supplies the frequency number R output from the frequency number memory 2 to the pitch interval adder 6. The pitch section adder 6 is connected to the gate 5.
Each time a frequency number R is supplied via (that is, each time a calculation interval timing signal is generated), the frequency number R is accumulated to obtain an accumulated value q that increases as IR, fox, ball, etc.
Output R. Then, the adder 6 overflows when the accumulated value qR exceeds the modulo N of the adder 6, and thereafter performs the same accumulation operation again every time the calculation interval timing signal is generated. Thus, the accumulated value qR, which changes with each occurrence of the calculation interval timing signal, is supplied to the harmonic interval adder 8 via the gate 7 gated by the clock pulse tc. In this case, since the clock pulse has a frequency W times that of the calculation interval timing signal, the gate 7 is opened W times during one cycle of the calculation interval timing signal. As a result, the harmonic section adder 8 sequentially adds the accumulated value qR output from the gate 7 every time a clock pulse occurs, and outputs the accumulated value nqR. When the adder 8 completes the accumulation W times, it is reset by the calculation interval timing signal 戊 and performs the same operation thereafter. Therefore, this harmonic interval adder 8 generates an accumulated value n which increases sequentially according to the clock pulse during one cycle of the calculation interval timing signal.
This means that qR (n=1, 2, 3...W) is generated. This accumulated value nqR is decoded by a memory address decoder 9, and the decoded output is supplied as an address signal to a sine function memory 101 which stores the amplitude value of each sample point of one cycle of the sine wave waveform at each address. , from the memory 0 to the sine amplitude value SinW kiln VqR
Read out. As is clear from the above explanation, the cumulative value qR of the pitch section adder 6 indicates the sequential sample points at which the musical sound wave amplitude should be calculated, and the cumulative value qR of the harmonic section adder 8 indicates the currently calculated sample point. It represents the phase of the n-th harmonic at each sample point qR inside. As a result, from sine function memory 0, the sine amplitude value sinW harmonic mqR (n = 1, 2
. . . W) are sequentially generated in the order of the fundamental wave (first harmonic), the second harmonic, and the W-th harmonic. In this case, the sample points of the musical waveform to be calculated shift sequentially every time the calculation interval timing signal tx is generated, but which sample point to shift to next is determined by the frequency number R. This frequency number R is proportional to the pitch of the operating key. Therefore, the sine amplitude value (SinW-qR) of each harmonic corresponding to the pitch of the operating key is sequentially generated from the sine function memory 0 in a time-sharing manner. On the other hand, the memory address control device 11 is composed of a modulo W counter, and sequentially counts clock pulses tc in synchronization with the counter 4, and sends the count value to the harmonic coefficient memory 12 as an address signal n.
Output as .

The harmonic coefficient memory 12 stores a harmonic amplitude coefficient C corresponding to the optimum amplitude value of each harmonic in order to obtain a desired musical timbre.
n is stored in each address, and when an address signal n (indicating the harmonic order) that changes sequentially in synchronization with the clock pulse tc is supplied from the memory address control device 11, the address signal n is stored in each address. A harmonic amplitude coefficient Cn that sets the amplitude value of each harmonic is sequentially read out. This harmonic amplitude coefficient Cn is output to the harmonic amplitude multiplier 13. The harmonic amplitude multiplier 13 converts the sine amplitude value sinW Kubokawa qR of each harmonic, which is read out from the sine function memory 0 in a time-sharing manner for each sample point, and the harmonic amplitude coefficient Cn set for each harmonic. and the multiplied value Fn=CnSi
Supply nW empty hqR to the accumulator 14. In this case, since the memory address control device 11 is synchronized with the harmonic interval adder 8, the harmonic amplitude coefficient Cn sequentially read out for each harmonic is the corresponding harmonic sine amplitude value sin mqR
This sets the amplitude value Fn for each harmonic. The accumulator 14 sequentially accumulates the amplitude value Fn for each harmonic output from the harmonic amplitude multiplier 13. Then, when the calculation interval timing signal 戊 is generated, the gate 15 opens and the accumulated value of the accumulator 14 (representing the amplitude value at a certain sequential sample point of the musical sound waveform) is converted to D-A.
At the same time as output to the converter 16, the accumulator 14 is reset and performs the same accumulation operation as described above again in order to calculate the amplitude value at each next sample point. Therefore, the D-A converter 16 calculates the amplitude value (digital signal) at the sample point of the musical sound waveform with a cycle corresponding to the pitch of the pressed key and a waveform shape set by each harmonic amplitude coefficient Cn. This digital amplitude value is input every time a section timing signal is generated, and by converting this digital amplitude value into an analog signal and supplying it to the sound system 17, the pitch corresponding to the pressed key is stored in the harmonic coefficient memory 2. A musical tone having a tone corresponding to the stored harmonic amplitude coefficient Cn is generated. On the other hand, an amplitude envelope is assigned to a generated musical tone in the following manner.

That is, the sound system 17 is provided with an envelope waveform generator that starts operating in response to the key-on signal KON' output from the key switch circuit 1 when any key is pressed. Enbe output from the generator. The musical tone signal is multiplied by the loop waveform to impart amplitude envelopes such as attack, sustain, and decay to the generated musical tone. Incidentally, since an electronic musical instrument having such a structure is disclosed in Samurai Publication No. 48-90217, a detailed explanation of the structure and operation of each part thereof will be omitted.

B. Disadvantages of the follow-up technology As is clear from the above explanation, the conventional harmonic synthesis electronic musical instrument described above generates a frequency number R corresponding to the pitch of the pressed key, and uses this frequency number R as the calculation interval timing. The signal is accumulated sequentially every time the signal is generated, and the accumulated value q specifies the sample point at which the musical waveform should be calculated.
By sequentially accumulating this accumulated value qR at the timing of the clock pulse tC, the sine amplitude value si of each harmonic at the sample point (qR) is obtained.
The cumulative value Asahi R for generating nW kiln-qR is formed.

Therefore, the musical tones generated in this way have an integer multiple (overtone) of the frequency (period) of each harmonic (including the fundamental wave).
The relationship becomes a harmonious musical tone. However, musical tones produced by natural instruments generally exhibit anharmonicity in which the frequency of each harmonic deviates from an integer multiple of the fundamental wave (first harmonic), resulting in a rich natural sound. It becomes.

However, it has not been possible to easily generate nonharmonic musical tones in the above-described conventional harmonic synthesis system. Incidentally, U.S. Pat. A new value must be added to nqR as an overtone offset value, which complicates the configuration and increases the overtone offset value for each order (each harmonic).
This method has the disadvantage that it is not possible to freely set the desired anharmonicity by setting the offset value arbitrarily. C. Purpose and Overview of the Invention The present invention was made in view of the above-mentioned drawbacks of the conventional harmonic synthesis type electronic musical instrument, and its purpose is to reduce the degree of anharmonicity of each harmonic with a simple configuration. The aim is to provide an Atsuko musical instrument that can be freely configured.

In order to achieve the above-mentioned object, in this invention, a frequency number R (natural number) corresponding to the pressed key pitch, a logarithmic frequency number o obtained by logarithmizing this frequency number R, and an order corresponding to the order of each harmonic. A logarithmic order number lo group obtained by logarithmizing Nasoba n (integer), a logarithmic anharmonic number o group obtained by logarithmizing a numerical value k (a number including a decimal point) indicating the degree of anharmonicity of each harmonic are generated, and this logarithmic frequency number lo
gR, logarithmic order number lo suppression and logarithmic non-discussion number l
ogk is arithmetic processed (added) to create a numerical signal logk group, and further this numerical signal lo rate nR is converted to a natural number numerical signal k group, and this numerical signal knR and frequency number R (
A numerical signal R'=nR+k for each harmonic order to which an anharmonic degree is given by arithmetic processing (addition) with the numerical group indicating the above-mentioned order (natural number) and the numerical group indicating the above order, a harmonic frequency number R for each harmonic order is obtained. By repeatedly accumulating this numerical signal R' = + knR for each harmonic, an accumulated value qR' is formed for reading out the sine amplitude value of each harmonic at sequential sample points of the generated musical tone. , and by setting k of the logarithmic anharmonic number lo scale to an arbitrary value of 1 or less, a musical tone with anharmonicity added by k clothing to the basic pitch determined by nR is generated. By appropriately changing the harmonic number k, a free non-harmonic musical tone can be obtained for each harmonic.

○ Explanation of the configuration and operation of the present invention [11 Explanation of the configuration of the present invention Fig. 2 is a block diagram showing an embodiment of the electronic musical instrument according to the present invention, and the same parts as in Fig. 1 are explained using the same symbols. is omitted.

In the figure, 18 is a frequency number memory that stores the frequency number R corresponding to the pitch of each key as a logarithmic value of logR (lo station is called a logarithmic frequency number), and 19 is a clock pulse output from a clock oscillator. Harmonic order signal n (n = 1 to
20 is an order number memory addressed by the harmonic order signal n output from the counter 9, and each address of this order number memory 20 has a value for each harmonic. The order number n, ~nW (integer) corresponding to the order of is the logarithm value logn, ~
(logn, ~log~ is generally set as logn:n=n, ~nW, and this is called a logarithmic order number). 21 is an anharmonic number memory addressed by the harmonic order signal n output from the counter 19, and each address of this anharmonic number memory 21 has a numerical value k indicating the anharmonic degree for each harmonic order. ,~k
W (an integer less than or equal to 1) is stored as a logarithmic value ogk, ~log kW (which may be negative).
is generally taken as lo scale: k=k, ~kW, which is called a logarithmic anharmonic number).

22 is the sum of the logarithmic order number lo leg output from the order number memory 20, the logarithmic anharmonic nasovar lo leg output from the non-discussion number memory 21, and the logarithmic frequency number o station output from the frequency number memory 18. 23 is a logarithm-to-natural number converter that converts the addition output logk output from the adder 22 into a natural number knR; 24 is a logarithm-to-natural number converter that converts the addition output logk output from the adder 22 into a natural number knR; A gate 25 opens to output the frequency number R (natural number) output from the frequency number memory 2 when the clock pulse tc is generated. The integrated value ship (n; 1, 2, 3...
...W), 26 is a numerical signal k (natural number) output from the logarithm-to-natural number converter 23 and the adder 2
27 is a W-stage shift register that performs a shift operation based on the clock pulse, and 28 is an adder that adds the numerical signal (natural number) output from 5 and outputs the added value R' = nR + knR. The numerical signal (added value) R' output from the shift register 26 is added to the output qR' of the shift register, and the added value (R' + qR') is sent to the shift register 2.
7, and in this case, the output R of the adder 26 is input to the adder 28.
′ (= 10 kNR) and the output nR of the shift register 27
are related to the same order number (n, to nw), and both are synchronized with each other.

Therefore, the shift register 27 and the adder 28 are
The numerical signal R' output from the adder 26 is sequentially accumulated for each order number (every n, to nW) to obtain an accumulated value pR(IR,
Wave ′, Shigeru ′...)
This makes up 9. Then, the cumulative value qR'(IR', Y'.
) is supplied to the memory address decoder 9 and becomes an address signal for addressing the sine function memory 10.

Therefore, the sine function memory 10 stores the sine amplitude value sinR' of each harmonic at the sequential sample points of the musical sound waveform, as in the case of FIG. =sin q(nR+k
rudder)) is the first harmonic (fundamental wave), the second harmonic, etc.
. . . Read out in a time-divisional manner in the order of the W-th harmonic. ■ Operation description of this embodiment In the electronic musical instrument configured as described above, when a certain key on the keyboard section is pressed, the corresponding key switch of the key switch circuit 1 closes and the corresponding output line of the key switch circuit 1 is closed. A “1” signal is output.

The output signal from this key switch circuit 1 is divided into a frequency number memory 2 storing a frequency number R and a frequency number memory 1 storing a logarithmic frequency number o station.
8 and read out the frequency number R and the logarithmic frequency number logR from the respective memories 2 and 18.
On the other hand, the counter 19 counts clock pulses and sequentially outputs harmonic order signals n (n=1 to w).
The order number memory 20 and the anharmonic number memory 21 are addressed by this harmonic order signal n and sequentially generate the logarithmic order number ogn(n, .about.nw and the logarithmic nonharmonic number o sphere), respectively.

In this case, the harmonic order signal n output from the counter 19 is Q. 1, 2...W, 1 at the timing of the Tsuku pulse
In order to sequentially change the order number memory 20, each logarithm order number lo Yanagi, lo Yanagi 2... lo
The timing signals for each calculation interval are sequentially read out at the timing of the clock pulse. Similarly, from the non-discussion number memory 21, each log non-discussion number lo
gkl~lo scale 2...logkW is read out sequentially.
The logarithmic frequency number o station, the logarithmic order number logn, and the logarithmic non-discussion number lo part generated in this way are added in an adder 22, and the added value lo sphere nR is inputted to a logarithm-to-natural number converter 23.

The logarithm-natural number converter 23 receives the input sum value lo part nR.
is converted into a numerical signal k of natural numbers, and this logarithm −
The natural converter 23 outputs a numerical signal k which sequentially changes and repeats k, n, R, k2n2R, . . . kwmwR at the timing of the clock/gust tC. Further, the frequency number R (natural number) read out from the frequency number memory 2 is input to the adder 25 via the gate 24 every time the clock pulse tc occurs, and the adder 25 inputs IR, bait, wave, etc. . . , and this integrated value nR is supplied to the adder 26. The integrated value rudder outputted from the adder 25 is added to the numerical signal k outputted from the logarithm-to-natural number converter 23 in an adder 26, and the added value nR + k = R' is added to each adder 26. It is output as a numerical signal (harmonic frequency number) R with a different degree of anharmonicity for each harmonic. This numerical signal R' is the accumulator 2
In the adder 28 of 9, the output qR of the shift register 27
and is supplied to the first stage (input side) of the shift register 27, where it is sequentially shifted by the clock pulse tc. In this case, in the initial state, the contents of each stage of the shift register 27 are all zero, so in the first calculation interval timing signal tx,
Numerical signal R output from adder 26 for each harmonic order
' is as it is (R, ', R2'...RW) to each stage of the shift register 27.
... is stored as R'w. Then, in the second calculation period timing signal 2, the accumulated value qR' is output from the shift register 27 as IR,', IR'2, . . . of q=1.
... IR'w is sequentially output, and the accumulated value qR' (q=1) of this shift register 27 and the numerical signal R' (R, ', R2'...・Rw
') are added in the adder 28, and the added value R',
1IR, (f',) is supplied to the first stage of the shift register 27. Therefore, in the second calculation interval timing signal t right, the contents of each stage of the shift register 27 are respectively station, ', next 2', station w', and the contents of each stage (sphere, ', next 2'... sphere 'w) is shifted to shift register 2 at the timing of clock pulse tC in the period for the next calculation interval timing signal t.
It is output sequentially from 7 onwards. By performing such operations sequentially, the accumulator 29 generates the sine amplitude value sinW(R') of each harmonic that appears at the sequential sample points of the musical sound waveform (corresponding to qR in FIG. 1). The same accumulated value qR' as shown in FIG. 1 (with non-controversiality added) is sequentially output for each harmonic order. The accumulated value qR' from the accumulator 29 is converted into an address signal in the memory address decoder 9, and then addressed to the sine function memory 0 to obtain the sine amplitude value sinw of each harmonic at sequential sample points of the musical waveform. Read band qR'.

The sine amplitude value sin qR' of each harmonic is multiplied by the harmonic amplitude coefficient Cn supplied from the harmonic coefficient memory 12 in the harmonic amplitude multiplier 13 to set the amplitude value of each harmonic, and the amplitude value of each harmonic is set. The accumulated value name is accumulated in the circuit 14 and sent from the gate 15 for each timing signal interval W. Fn, that is, the amplitude value Fn of each harmonic at the forward sample point of the musical sound waveform is synthesized and output.

Then, from this gate 25, a calculation interval timing signal t
The sequential sampling point amplitude values of the musical waveform of the digital signal that are sequentially output in synchronization with
After an amplitude envelope is applied to the sound, it is generated as a musical tone. In this case, each logarithmic order number b law (logn, l
o law W) determines the fundamental pitch of each harmonic,
n・=1.0, n2 so that each value of n has an integer multiple relationship.
=2.0, ratio=3.0...n,6=16.0.

In addition, each address of the non-harmonic number memory 21 is used to set the non-harmonicity (deviation from the fundamental pitch) of each harmonic, and the value of each k is set to a decimal number of 1 or less, for example, k,=0.
001,k2=0.002,k3=0.003,k,6
=0.016.

In this way, when different logarithmic anharmonic number lo spheres are stored in each address of the anharmonic number memory 21, the numerical signal lo part nR output from the adder 22 is obtained by adding logk, which is different for each harmonic, to the logarithmic number memory 21. It became something that
Numerical signal knR output from logarithm-natural number converter 23
is k, n, R=0.001R, k2n2R=○-004
R,k3n3R=○-00 rule R,...k,6n. 6R
= 0.25 stations.

Therefore, the output R' of the adder 26 is R,'=1.001R
, R2'=2.004R, R3'=3.00 stations,...
. . .R,6=16.25 waves, which is a harmonic frequency number to which a different degree of anharmonicity is assigned for each harmonic order. Therefore, the cumulative value qR' output from the accumulator 29 is slightly deviated from the integral multiple relationship for each harmonic, and the sound system 17 generates a non-coherent musical tone. Therefore, by arbitrarily varying the logarithmic non-discussion number lo scale stored in the non-harmonic number memory 21, it is possible to easily vary the degree of anharmonicity for each harmonic order. In this case, the order number n is slightly shifted from the integer multiple relationship for each harmonic (n=1.0, n2=2.00
1... n, 6 = 16.016) A method of obtaining non-harmonic musical tones can also be considered, but n, = 1.000, n2 = 2.
001・・・・・・If n・6=16.016, n
is "integer part (basic pitch) decimal part (pitch deviation)"
becomes. Therefore, when trying to obtain various types of incompatibility,
It is necessary to prepare a large number of numerical values n consisting of an integer part and 10 decimal parts, which increases the memory size. However, in this invention, only the integer part is set for n, and the decimal part is set by k, so to change the anharmonicity, k
It is only necessary to change
Since the number of bits is smaller than the number of bits (integer part + decimal part), even if a large number of k are prepared, the memory size will not increase that much. In other words, it has an excellent effect of being able to freely set the degree of anharmonicity for each harmonic order with a simple configuration. In this way, in the electronic musical instrument with the above configuration, the anharmonicity of the generated musical tone can be freely changed for each harmonic, and the multiplication value of the frequency number R, harmonic order number n, and anharmonic number k can be changed. , these numbers R, n, and k are logarithmized and the logarithmized numbers lo, logn, and logk are obtained by addition processing, so that the configuration can be made simpler than when a multiplier is used.

In addition, since the k-elbow is to set the deviation for anharmonicity, the means for generating knR (logR, lo law, l
(oscale) does not require high precision, and this allows various anharmonicities to be obtained without increasing the memory size.

E Other Embodiments According to the Invention Explanation of the Structure of this Embodiment FIG. 3 is a block diagram showing another embodiment of the electronic musical instrument according to the invention, and the same parts as in FIG. 2 are designated by the same reference numerals. .

The difference between this figure and FIG. 2 is that the inharmonic number memory 21 is also addressed by the frequency number M. In this case, the non-harmonic number memory 21 has memory groups corresponding to the number of frequency numbers R supplied as address signals, and the non-harmonic number lo spheres stored in each of these memory groups are different. Therefore, in an electronic musical instrument having such a configuration, the incoherence of the generated musical tones differs for each harmonic and also differs depending on the pitch of the operating key.

In addition, in the embodiments of FIGS. 2 and 3 described above,
The integrated value of the frequency number R (natural number) is integrated using an adder, but the harmonic order signal n output from the counter 9 and the frequency number R are calculated by the multiplier You may try to get some clothes.

F Effects of the Invention As explained above, the electronic musical instrument of the invention has a frequency number R (natural number) corresponding to the pitch of the pressed key, and a logarithmic frequency number ogR obtained by logarithmizing this frequency number R.
, a logarithmic order number logn obtained by logarithmizing the order number n corresponding to the order of each harmonic, a logarithmic anharmonic number log obtained by logarithmizing the numerical value k indicating the degree of anharmonic of each harmonic. o station, logarithmic order number log
Arithmetic processing (addition) of n and the logarithmic anharmonic number lo sphere produces a numerical signal lo sphere nR, and furthermore, this numerical signal lo
The part nR is converted into a natural number numerical signal knR, and this numerical signal k is processed (added) with the calculated value of the frequency number R (natural number) and the numerical value n indicating the order to give an anharmonic degree. By creating a numerical signal R2knR for each harmonic order and repeatedly accumulating this numerical signal R' for each harmonic, the sine amplitude value of each harmonic at sequential sample points of the generated musical tone can be read out. By forming an accumulated value qR' and generating each anharmonic number k as an arbitrary decimal value of 1 or less, various anharmonic musical tones can be obtained.

Therefore, with a simple configuration, it has excellent effects such as being able to freely change the anharmonicity of the generated musical tones for each harmonic and for each operated key tone.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an electronic musical instrument using a secondary harmonic synthesis method, and FIGS. 2 and 3 are block diagrams showing an embodiment of the electronic musical instrument according to the present invention. 1...Key switch circuit, 2,18...
・Frequency number memory, 3... Clock oscillator, 4, 19... Counter, 9... Memory address decoder, 10... Sine function memory, 14...
... Accumulator, 15, 24 ... Gate, 17 ... Sound system, 20 ... Order number memory, 21
・・・・・・Nonharmonic number memory, 22, 25, 26,
28... Adder, 23... Logarithm-to-natural number converter, 27... Shift register, 29... Accumulator. Map of the ship

Claims (1)

[Claims] 1. A musical tone is generated by generating components corresponding to the fundamental wave and its harmonics constituting a musical tone, multiplying each component by a corresponding amplitude system, and synthesizing the multiplied values. In the harmonic synthesis electronic musical instrument, the frequency number generating means generates a frequency number corresponding to the pitch of a pressed key and a logarithmic frequency number obtained by logarithmizing this frequency number, and an order number corresponding to the order of each component. from the frequency number generation means; an addition means for adding the generated logarithmic frequency number, the logarithmic order number generated from the order number generation means, and the logarithmic anharmonic number generated from the anharmonic number generation means; and converting the output of the addition means into a natural number. A logarithm-to-natural number converting means for converting, a calculating means for calculating the frequency number generated from the frequency number generating means and a numerical value indicating the order of each of the components, and an output of the calculating means and the logarithm-to-natural number converting means for calculating and an accumulating means for repeatedly accumulating the output of the accumulating means for each of the above components at a predetermined speed. An electronic musical instrument characterized in that each of the above components is generated by addressing a sine function memory storing sample point amplitude values at each address. 2. The anharmonic number generation means sequentially addresses a memory storing a logarithmic anharmonic number obtained by logarithmizing a numerical value indicating the degree of anharmonicity of each component with a signal indicating the order of each component, and 2. The electronic musical instrument according to claim 1, wherein a corresponding logarithmic anharmonic number is generated. 3. The anharmonic number generation means outputs a memory storing a logarithmic anharmonic number obtained by logarithmizing a numerical value indicating the anharmonic degree of each component, and a signal indicating the order of each component from the frequency number generation means. Claim 1 is characterized in that a logarithmically anharmonic number corresponding to each of the components is generated by addressing a frequency number corresponding to each component.
Electronic musical instruments listed in section.