Interval

The distance in pitch between two notes, named by counting the letter names between them and qualified by whether they are major, minor or perfect.

Intervals are what give chords and melodies their character, since a third decides whether a chord is major or minor, a fifth supplies stability and a seventh or ninth adds tension. On the guitar, every interval has a shape or shapes on the neck, so a player who knows them can construct a chord or a line anywhere rather than memorising diagrams. Tuning in fourths with one major third makes some intervals fall under the same shape wherever they start.

Example: moving a shape up two frets raises every note by a whole tone, which is a major second, and the chord keeps its quality.

Interval

See also