Nippon Gakki Seizo Kabushiki Kaisha

Yamaha Corporation

Akiyoshi Oya

Akira Nakada

Yasuji Uchiyama

Eiichiro Aoki

Takatoshi Okumura

Eiichi Yamaga

Akio Imamura

Hideo Suzuki

Shigeru Yamada

Naoyuki Niinomi

Tomoaki Sekiguchi

Tutomu Suzuki

Takashi Ubayama

In this electronic musical instrument a musical tone is generated by repetitively reading out a waveshape stored in a memory. Repetitive sets of phase information are produced, such phase information thus being a linear saw-tooth-like digital signal having a repetition period corresponding to the frequency of the generated musical tone. Phase distorting means modifies the shape of the phase information so as to distort said linear saw-tooth-like signal, without changing the repetition period thereof. The resultant altered phase information is used to access said memory so that during the supply of each of said repetitive sets, successive samples in different portions of said stored waveshape respectively are read out at different effective rates. Thus the waveshape samples read out from said memory will constitute a musical tone having changed tone color but unchanged pitch.

Electronic musical instrument including waveshape memory and modifiable

In this electronic musical instrument a musical tone is generated by frequency modulation employing a carrier wave and a modulating wave. Plural tone production channels are employed and a key assigner assigns production of a tone corresponding to a depressed key to an available channel. Tone production is achieved by a frequency modulation operation carried on in a time-shared manner for each channel. In order to achieve complex variation in harmonic content of the tone signal which is generated, the frequency of the carrier wave varies with the passage of time.

Electronic musical instrument employing time-sharing frequency

In this electronic musical instrument a musical tone is generated by repetitively reading out a waveshape stored in a memory. Repetitive sets of phase information are produced, such phase information thus being a linear saw-tooth-like digital signal having a repetition period corresponding to the frequency of the generated musical tone. Phase distorting means modifies the shape of the phase information so as to distort said linear saw-tooth-like signal, without changing the repetition period thereof. The resultant altered phase information is used to access said memory so that during the supply of each of said repetitive sets, successive samples in different portions of said stored waveshape respectively are read out at different effective rates. Thus the waveshape samples read out from said memory will consitiute a musical tone having changed tone color but unchanged pitch.

An electronic musical instrument capable of producing, by frequency modulation, a musical tone containing harmonic components of integer and non-integer orders at complicated ratios which change with time. In frequency modulation, amplitudes of carrier and side frequencies are preceded by a positive or negative sign depending upon a value of modulation index. By suitably setting the value of modulation index, phase inversion occurs in the side frequencies so that cancellation or augmentation of amplitude will occur between side frequencies of the same frequency. By utilizing this phenomenon and also the fact that the harmonic spectrum can be varied by varying the carrier and the modulating waves, the electronic musical instrument according to the invention produces a musical tone containing extremely complex harmonic components. An embodiment of the invention is disclosed in which a single sinusoidal carrier is frequency modulated by a single sinusoidal modulating wave to provide the frequency modulated wave as a musical tone signal. In this embodiment, the phase component of the carrier wave, phase component of the modulating wave, modulation index and amplitude coefficient are all time-variant values. In another embodiment of the invention, a single sinusoidal carrier is frequency modulated by two sinusoidal modulating waves. Other examples are also disclosed in which function waveforms other than a sine wave and containing harmonics are used as the carrier and modulating waves.

Electronic musical instrument

A timbre modulation circuit for an electronic musical instrument having an automatic rhythm accompaniment system. The timbre modulation circuit is provided in a musical scale tone signal path and includes a means for generating a control pulse series synchronized with an automatic rhythm sound generation timing and a variable timbre circuit responsive to the control pulse series whereby the timbre characteristics are caused to vary in response to the control pulse series thereby modulating the timbre of the musical scale tones.

Timbre modulation circuit for electronic musical instruments

An electronic musical instrument comprises a tone generator which generates tone signals having tone pitches as designated by playing keys and tone properties as determined by control data signals applied thereto. A set of control data signals are provided in a digital format and delivered timewisely in serial form to manual setting units. The serial signals are converted into parallel signals and applied to the respective setting units for desired adjustment. The adjusted or non-adjusted parallel signals are converted back into serial signals and applied to the tone generator. Interpolator circuits are provided between the setting units and the tone generator to apply the latter control data signals whose values vary gradually even when the values of the signals from the setting units exhibit abrupt large changes from certain values to another.

Electronic musical instrument controlling tone properties by control

In an electronic musical instrument, there are provided a main musical tone generator for producing a main musical tone and a submusical tone generator for producing a submusical tone different from the main musical tone. The main musical tone generator has a plurality of tone production channels smaller than a total number of keys, the assignment of key information data corresponding to a depressed key to the tone production channel is changed according to a performance mode. The tone production channels and the key information data corresponding to depressed keys are divided into at least two groups respectively in the case of performance mode. One group of the tone production channels is assigned to one group of the tone production channels to produce the main musical tone for an automatic accompaniment, whereas another group of the key information data is assigned to the remaining group to produce the main musical tone for melody. In the submusical tone generator the key information data corresponding to the highest tone among the main musical tones for melody is used to produce the submusical tone.

Electronic musical instrument with special tone generator

A root note detection circuit detects the highest or lowest key among depressed keys in an accompaniment key range as a root note designation key. A root note memory stores the detected root note data and rewrites its storage each time the detected root note data changes. A chord type detection circuit detects a chord type in accordance with states of depression of keys other than the detected root note designation key in the accompaniment key range. The detected chord type data is stored in a chord type memory by being controlled by outputs of a root note change memory and a new key detection circuit. The root note change memory detects change in the root note by comparing the output of the root note detection circuit with the output of the root note memory and outputs a root note change signal during a preset waiting timing. Accordingly, the data stored in the chord type memory can be rewritten not only upon detection of depression of a new key but during this waiting time. False chord type data which is temporarily detected when the root note designation key is changed in a legato style ceases to be detected within this waiting time so that correct data is finally stored in the memory. A chord is determined by the root note data and the chord type data stored in these memories.

Chord generating apparatus of an electronic musical instrument

A digital oscillator generates a basic pulse having a period which is a predetermined large number of times of a clock pulse period. During the basic pulse period are allotted a predetermined small number of time slots defining submultiple frequency channels. There is provided a shift register having the channel number of stages, each stage being assigned to each channel. The contents of the respective stages are changed at respectively different periods which are multiples of the basic pulse period. The contents are taken out timewise-serially, one at a time, stage by stage, and superimposed on the basic pulse to constitute a time-division-multiplexed wave data signal. The delivered signal is demultiplexed to form individual waves having respectively different frequencies which are submultiple-related to the frequency of the basic pulse. This generator is very suitable for electronic musical instruments, as a single line transmits plural wave data.

Submultiple-related-frequency wave generator

An automatic performance device comprises a pattern memory for storing a plurality of performance patterns and a sequence memory for storing a pattern progression. The pattern progression is programable and is written in the sequence memory. The performance patterns are selected one by one from the pattern memory according to the pattern progression. Each selected performance pattern is read out according to a tempo pulse. An automatic performance is carried out on the basis of the read-out performance pattern.

Automatic performance device

An electronic musical instrument having a plurality of keys is provided with a depressed key detector which detects depressed keys and produces key identifying signals; a highest signal detector which detects a highest one among the key identifying signals having a highest priority in accordance with a predetermined order of priority; a musical tone producing unit responsive to the detected highest signal for producing a musical tone of a tone pitch corresponding to the highest signal; a reference memory device for storing the detected highest signal in accordance with a predetermined condition; and a controller for inhibiting the musical tone producing unit from producing the musical tone according to a relationship between the detected highest signal and an output of the reference memory device. Thus the progression of simultaneous plural key depressions provides a melody performance including rests.

Electronic musical instrument with highest priority key tone production

A display device for an automatic rhythm performance apparatus comprises a common display unit which selectively displays tempo and rhythm advancement of the automatic rhythm performance. For this purpose, the device has a selector for selecting the display contents so that the display of tempo is performed by numerical value before the rhythm starts, and the display of the rhythm advancement is performed by the number of measures, the number of beats and a demarcating mark between them after the rhythm starts.

Display device for automatic rhythm performance apparatus

An electronic musical instrument is of a time-shared digital processing type and capable of producing musical tones for a special performance. There are provided, at suitable time intervals, time periods in which no key code of a depressed key is produced by a key coder. During these time periods, a signal designating a special performance is generated. In a channel assignment circuit which assigns key codes of depressed keys to plural tone production channels there is provided a channel for an exclusive use for the special performance. A circuit for assigning data for the special performance transmits the data to the channel assignment circuit in response to the special performance designation signal from the key coder so that the data selected from among the key data already assigned to the tone production channels for ordinary performance are sequentially assigned to the channel allotted exclusively for the special performance. As an example of the special performance, description is made with respect to an automatic arpeggio performance in which tones are produced at designated orders of location from the lowest tone among the tones of the depressed keys.

Electronic musical instrument of time-shared digital processing type

Key switches are connected in a matrix fashion between row lines making block lines for octaves and column lines making note lines for notes. The note lines are connected to a note detection circuit which converts the note line outputs of the actuated switches into key codes in a time shared fashion and to a chord detection circuit which includes a chord type detecting logic and a shift register connected thereto and storing the note line outputs in its respective stages. During a chord detecting period, the note detection circuit is loaded with signals '1' as if all the key switches were actuated and delivers key codes of all notes one after another, whereas the shift register is circulatingly shifted synchronously with the note code change. When the logic detects an establishment of a chord, the note code of that moment is extracted to be a code identifying the root note of the chord. The root note code is then processed for automatic bass and chord performance.

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Hamamatsu, Japan

Akiyoshi Oya