Scales

A scale is a set of ordered notes used in a particular piece of music. A scale usually is defined in terms of notes that move between octaves. An octave, in guitar terms, is formed by two notes when one note is made on a string exactly half the lenght of the other note. In this diagram the two notes forming the C octave are marked. You can also play an octave by playing an open note then the same string fretted at the 12th fret (exactly halving the length). The Fret diagram shows a particular set of notes (a C major scale) that will sound familiar if you play them.

In the following video you can hear the low and high C, a low E and high E at the twelth fret, and the C scale above.