Abstract: A signal analysis device for determining the pitch of a plucked string in which propagation times of plucking transients are evaluated to determine pitch. A neural network may be employed to perform evaluation based upon groups of pulses.

Abstract: A method is specified for pitch recognition, in particular for musical instruments which are excited by plucking or striking, in the case of which method the interval between zero crossings of a signal waveform of an audio signal is used as a measure for the period length of the audio signal.Reliable pitch recognition is intended to be possible in a simple manner using such a method. The method is intended to be capable of being implemented with a low level of computation power.To this end, the magnitude of the gradient of the signal waveform is in each case determined in the region of its zero crossings, and the magnitude of the gradient is used as an assessment criterion for the selection of the zero crossings to be evaluated.

Abstract: An musical information analyzing apparatus operates in a data-processing manner and segments a melody of a given music into phrases so that each phrase should be recognized by the human ear as a note string to be demarcated in grasping musical sensation, detects a musical scale prevailing in the phrase and determines a key of the phrase. In the phrase segmentation process, a rest duration datum is added to the preceding note duration datum. An average note duration is computed, and notes having a long duration with respect to the average note duration is set to constitute the phrase end. Several adjustments are conducted to improve the segmentation. The scale is detected by computing a scale establishment rate based on the note use rate in the phrase. An adjustment is performed to smooth the musical flow. A key is determined by computing a major/minor degree of the notes.

Abstract: A method is disclosed of modification of parameters of audio signals by dividing a digital signal converted from an original analog signal into sound frames, modifying a pitch and a playing rate of the digital signal within a frame and subsequent successive splicing a last modified frame with a first non-modified frame and calculating a differential mean absolute error to define the best splicing point in terms of producing minimal or no audible noise such that various sections of sound signals can be spliced together to achieve pitch and playing rate modification. An apparatus is also disclosed for implementing the method, the apparatus comprising input and output amplifiers, a low pass filter at the input and a low pass filter at the output, analog-to-digital and digital-to-analog converters, and a pitch shifting processor.

Abstract: A method and device for very quickly and accurately determining the fundamental frequency of an input analog electrical signal. The method first uses sparse range autocorrelation to determine the note which is closest to the fundamental frequency. It then uses fine range autocorrelation and interpolation to calculate more precisely the exact pitch. Smoothing is employed for both the sparse range determination and the subsequent fine range determination to reject spurious signals. Because the sparse autocorrelation produces good results with merely one or two full cycles of the fundamental frequency, the initial sparse determination can be made in less than ten milliseconds and this is updated with a fine determination less than two milliseconds later.

Abstract: A karaoke sound processor that automatically adjusts to the pitch of the singer's voice is provided. The pitch of the song signal recorded in the accompaniment recording medium for karaoke is detected by a first pitch detecting facility. The pitch of the song signal of the singer entered from the microphone is detected by a second pitch detecting facility. The two song signal pitches are compared in a comparing facility. When the pitches of the two signals are different, the output signal of the accompaniment is automatically changed by a pitch changing facility. The output signal of the pitch changing means and the signal of the microphone are summed up by an adder and produced. Without requring the singer to set the pitch change value, a karaoke sound processor capable of correcting the pitch automatically to a register comfortable for the singer is provided.

Abstract: A sound constituting apparatus translates a sensor output, as detected by an input detection unit, such as state changes, into electrical signals. A data extracting unit makes use of these electrical signals as an information concerning an external environment to extract the results of analyses of the information concerning the external environment as data. A sound source controlling unit outputs sound source controlling data, based on the data extracted by the data extracting unit, and translates the output signals into a modified sound by a sound producing device to eliminate time constraint.

Abstract: A musical tone signal forming device for an electric string music instrument having at least one pickup for detecting and delivering vibration of a string as an electric musical sound signal, including at least one comb filter having the electric musical sound signal as an input thereof; and structure for producing parameters corresponding to a specific position, which differs from a position of the pickup with respect to the string, at which an imaginary pickup is disposed and a reference vibration frequency of the string and supplying the parameters to the at least one comb filter to determine a frequency characteristic of the at least one comb filter, wherein the frequency characteristic of the at least one comb filter simulates a frequency characteristic of the electric musical sound signal delivered from the imaginary pickup disposed at the specific position.

Abstract: A CPU measures the interval between the zero-crossing points at the two ends of a waveform element a having, e.g., a positive polarity. Thereafter, the CPU sequentially measures the interval between the zero-crossing points at the two ends of each of waveform elements b, c, and d having the same polarity. Upon detection of the waveform element d which is almost equal in interval to the waveform element a and is located nearest thereto in terms of time, the interval between the start points (zero-crossing points) of the waveform elements a and d is extracted as the pitch period of the input waveform. Subsequently, the above-described series of operations is repeated.

Abstract: An apparatus for discriminating a received audio signal as vocal sound or musical sound includes a pre-processing circuit 100 for separating the audio signal into a vocal frequency band signal and a musical frequency band signal, an intermediate decision circuit having a plurality of decision units for producing a plurality of vocal and musical decision signals, each decision unit distinguishing whether vocal or musical frequency band signal includes properties of voice or music, and a final decision circuit 600 for systematically analyzing the vocal and musical decision signals to produce a final decision signal for discriminating the audio signal as the vocal or musical sound.

Abstract: An electronic musical instrument with playback of background tones and generation of key-on phrase tones, in which a simple adlib play can be performed while a user is singing using a microphone or as an interlude without requiring high-grade techniques is disclosed.The electronic instrument includes an instrument main body (1) having a microphone (5) and a plurality of key pads (6), a section for playing back stored background tones of a song, a memory (21) for storing note pattern data for a plurality of phrases each consisting of a series of a plurality of key-on phrases in correspondence with the plurality of key pads, and a tone generator (20) for reading out the note pattern data of the corresponding phrase in response to an operation of the key pad (6), and forming tone generation signals. The output from the microphone, the playback signals of the background tones, and the tone generation signals of the phrase are supplied to a loudspeaker (11).

Abstract: An electronic music system for computer-controlled interactive practicing and learning to play a guitar includes a transducer which is detachably securable to the guitar and generates analog signals representing the playing of the guitar, an interface for converting the analog signals to computer-processable digital signals, and a computer for receiving and processing the digital signals. The system uses a communication protocol which employs time stamping of data to permit use with ordinary guitars but without high speed frequency determination. The computer provides audio and video outputs including staff and guitar fingering representations of notes, chords, scales, compositions, and like musical structures, both to teach the user and suggest music to be played by the user and to illustrate what the user has played. The system is operable in several modes which may be controlled by the user by signals produced at the transducer.

Abstract: A system and method for detecting, separating and recording the individual voices in a musical composition performed by a plurality of instruments. The electrical waveform signal for the multi-voiced musical composition is fed to a waveform signal converter to convert the waveform signal to a frequency spectrum representation. The frequency spectrum representation is fed to a frequency spectrum comparator where it is compared to predetermined steady-state frequency spectrum representations for a particular musical instrument. Upon detecting the presence of a frequency spectrum representation corresponding to a predetermined steady-state frequency spectrum representation, the detected frequency spectrum representation and measured growth and decay frequency spectrum representations are fed to a waveform envelope comparator and compared to predetermined waveform envelopes, i.e. frequency spectrum representations during the growth, steady-state and decay periods of the waveform signal.

Abstract: A voice input to a microphone is converted by an A/D converter to a digital signal which is then delivered to a DSP, which extracts the notes of the input voice for determining same. The processing by the DSP includes bandpass filtering with a frequency corresponding to each note as the central frequency. A plurality of notes is processed on a time divisional basis to determine their respective notes. A new musical sound electronically corresponding to one or more notes extracted as the result of the note detection is then generated on a real time basis.

Abstract: A vibration of a string is picked up by a pickup to be converted to an electric signal. A pitch extracting circuit obtains pitch data expressing a pitch or a duration of the string vibration from the electric signal. A musical tone generating circuit generates a musical tone having a corresponding tone pitch in accordance with the pitch data. An envelope extracting circuit extracts an envelope from the electric signal detected by the pickup and supplies a signal expressing the envelope to a multiplier. Furthermore, a signal expressing the musical tone is supplied to the multiplier to be multiplied by the signal expressing the envelope. Thus a musical tone having a controlled envelope determined by the extracted envelope is generated.

Abstract: A plurality of strings are extended along a surface of a body, and an operation by a player with respect to the strings is detected by two detection systems. The first detection system is operated when a string vibration is started, and electrically obtains an operated fret position of the string by detecting an ON/OFF operation of a switch arranged below each fret. The second detection system is enabled after the first detection system is enabled, and directly measures a pitch period of the string vibration. The second detection system detects a change in pitch by a choking operation or an arming operation of a tremolo arm with respect to the string after tone generation is started.

Abstract: An electronic musical instrument extracts a pitch from an input waveform signal by a pitch extracting circuit, and directs a sound source circuit to generate a musical tone at the pitch based on the extracted pitch. The sound source circuit electronically generates musical tones at the pitches according to the performance. The pitch extracting circuit obtains fundamental period of the input waveform signal by detecting the time interval (t1) between these first two zero-cross points after two positive peak points of the input waveform signal are detected, by detecting a time interval (t2) between first two zero-cross points after two negative peak points of the input signal waveform are detected, or by detecting both the time intervals (t1, t2).

Abstract: An input waveform signal is first converted into a compressed waveform signal by log-conversion. The compressed waveform signal is then converted into a digital compressed waveform signal so that a pitch of the input waveform signal is extracted from the digital compressed waveform signal. Note-on/off states of a musical tone to be produced are controlled in accordance with the level of the digital compressed waveform signal and a predetermined threshold. The attenuation period of the input waveform signal and, thus, the note-on time, can therefore be prolonged to correspond more closely with the actual playing of an instrument from which the input waveform signal is obtained.

Abstract: To generate different frequencies, two accumulations are performed using the same calculation routine. This simplifies the system configuration and permits the fabrication of the whole system as a one-chip LSI.

Abstract: Data representing a pitch is extracted from an input waveform signal and a musical tone having a corresponding tone pitch is generated. By chromatically designating a tone pitch, a musical tone having a tone pitch of a semitone unit is generated from a sound source circuit at the starting of the input waveform signal. After tone generation is started, in the system for updating a tone pitch having an interval of less than a semitone interval, a musical tone is generated in accordance with various performances. Therefore, a musical interval after tone generation is started can be clearly recognized, thus obtaining an excellent musical performance effect.

Abstract: An electronic musical instrument comprising detection means to detect time positions of an initial part and a terminal part of a voice, extraction means to extract pitch data of the voice, a plurality of processing means to subject the pitch data to different processing operations, means to successively select the processed pitch data of the plurality of processing means in correspondence with the respective detected time positions, and musical sound production means to produce a musical sound on the basis of the processed pitch data delivered from the selection means.