Classical guitar fingerboard and placed at points that divide the length of string mathematically. The strings' vibrating length is determined when the strings are pressed down behind the frets. Each fret produces a different pitch and each pitch spaced a half-step apart on the 12 tone scale. The ratio of the widths of two consecutive frets is the twelfth root of two (formula_1), whose numeric value is about 1.059463. The twelfth fret divides the string in two exact halves and the 24th fret (if present) divides the string in half yet again. Every twelve frets represents one octave. This arrangement of frets
Vibrato systems for guitar An advantage or disadvantage, depending on taste, is string resonance audible at several fret positions where a simple relation exists between the length to the fret and the string length behind the bridge (for instance 48:12 = 4:1). At those positions, a high overtone rises in volume. This becomes clearer with an over-driven guitar sound. The overtone might sound odd, but it still has a harmonic relation to the note, so is not out of tune related to the open string. For staccato playing, it can be annoying. Muting the strings behind the bridge with felt or other material solves