When musicians ask themselves “why learn intervals?” often the answer is “to recognise notes by ear”.
Intervals can be seen as the “building blocks” with which melodies and harmonies are created, and so interval ear training helps you to pick apart these elements of music by ear and recognise the notes present.
Learning to recognise intervals improves your overall sense of relative pitch, and it is this musical sense which allows you to recognise notes, scales, chords, chord progressions and more.
However, where many music students get stuck is that even when you learn to recognise intervals, it is not immediately obvious how to use that new skill to recognise notes in music you hear.
There are three ways you can apply the knowledge of intervals to recognise notes by ear:
1. Recognise intervals between pairs of notes
With this approach, you use your interval recognition skills to “measure” the distances between note pitches by ear, and so work out the relationship between those notes. This then lets you identify each note based on the one before it.
For example, if you’re listening to the root note of a chord progression, you could apply your interval recognition skills to hear that the root of the second chord moves up a perfect fourth from the first one, so it must be the IV chord. Then the third chord in the sequence is a tone above that one, so it must be the V chord.
Or, you might hear that the intervals between the first three notes of a