Interval

From GuitarWiki

Intervals in music theory are the distances between two notes, the first note is usually named the 'root' note. Here are the intervals as applied against the root note C:

C + C (of the same octave) = perfect unison

C + Db (one semitone above) = diminished 2nd, or b9

C + D (one whole tone) = major 2nd (or 9th)

C + D# = augmented 2nd, or #9th (equivalent to minor 3rd, but technically any C to any D is a "2nd" or a "9th").

C + Eb (sounds the same as above) = a minor 3rd

C + E = a major 3rd

C + F = a perfect 4th, or 11th

C + F# = an augmented 4th, or #11th

C + Gb (sounds the same as above) = A diminished 5th, or a tritone

C + G = a perfect 5th

C + G# = augmented 5th, #5th

C + Ab = a minor 6th, b13th

C + A = a major 6th, 13th

C + A# = augmented 6th, or #13

C + Bb (sounds the same as above) = minor 7th

C + B = major 7th

These intervals can be stacked to create chords, every chord must contain 3 or more notes (2 intervals minimum) otherwise it is known as a harmony, These are commonly called: double-stops and power chords.

Below are the two most common types of chords and their interval formula's

Major:

Root, Major 3rd, Perfect fifth

Minor :

Root, Minor 3rd, Perfect fifth