Guitar synthesizer

DETAILED DESCRIPTION The present invention comprises a guitar synthesizer comprising a guitar portion and a synthesizer portion electrically connected to each other, characterized in that a guitar sound signal is generated from a string vibration caused by touching the strings of the guitar, such guitar sound signal including harmonics as well as a fundamental wave component.
The guitar sound signal is applied to a voltage controlled variable bandpass filter the passband characteristic of which is variable in at least two frequency regions of the frequencies of the fundamental wave component as a function of a control voltage.
The frequency of the output of the voltage controlled variable bandpass filter is converted into a voltage associated with the frequency of the output of the voltage controlled variable bandpass filter.
The frequency associated voltage is applied to the voltage controlled variable bandpass filter as a control voltage, so that the passband characteristics of the voltage controlled variable bandpass filter is adaptably and dominantly responsive to the frequency of the fundamental wave component included in the guitar sound signal, whereupon a fundamental wave associated signal having the same frequency as that of the fundamental wave component is generated.
An envelope signal representing the envelope of the guitar sound signal is also generated based on the guitar sound signal and a synthesized guitar sound is generated through synthesization of the above described fundamental wave associated signal and the envelope signal.
According to the present invention, even if a harmonic component is included toward the end portion of the guitar sound signal, a fundamental wave component can be extracted with accuracy from the guitar sound signal while the harmonic component is made less dominant or is removed from the guitar sound signal by extraction and the fundamental wave component is made dominant.
In a preferred embodiment of the present invention, a string vibration is detected individually for each of a plurality of strings of a guitar and the voltage controlled variable bandpass filter is adapted such that the passband characteristic thereof of each string is variable into two frequency regions of a higher frequency region and a lower frequency region depending on the positions of the frets of the guitar