An interval is the distance between two notes. Intervals shape melodies, build chords and make transposition possible. Hearing them also reduces the amount of trial and error needed when learning songs by ear.
Name and measure an interval
The number comes from letter names: C to E is a third. Its quality depends on semitones. C–E is a major third with four semitones; C–Eb is a minor third with three.
Useful intervals to learn first
- Major 2nd: 2 semitones.
- Minor 3rd: 3.
- Major 3rd: 4.
- Perfect 4th: 5.
- Perfect 5th: 7.
- Major 6th: 9.
- Octave: 12.
Intervals inside chords
A major triad uses root, major third and perfect fifth. A minor triad lowers the third. Hearing that third is one of the fastest ways to distinguish major from minor.
Train without guessing
Play two notes, sing the first and predict the second before checking. Work on one or two interval types at a time and practice both ascending and descending.
Apply intervals to transposition
If a song moves up two semitones, every melody note and chord root moves by that same distance. Thinking in intervals prevents partial or inconsistent transpositions.