A stringed musical instrument embodies a matrix of intersecting frets and strings. A generally rectangular fingerboard mounts the strings and frets in a generally intersecting relationship thereon. The strings are tuned by string tensioning means, including tuning pegs. The string vibrations are amplified by an amplifier and sensed by a magnetic pickup. The strings and frets each define a number of notes, equal to at least the number of notes of an octave. In a first scheme of modulation, a plurality of strings are played along a single fret in a manner similar to a piano, the octave and key linear distance spacings as well as notes, being emulated. In a second scheme of modulation, different frets are played to obtain different notes, as in a guitar, to achieve a wide tonal range with easy fingering positions. Vertically adjustable magnets pick up the vibrations and are able to change the vibration sensitivity of the instrument.