Understand
Intervals: Number and Quality
Measuring the distance between two notes by ear and on paper.
Class code
RB4NCount the letters first
The number of an interval comes from counting letter names inclusively: C up to E covers C, D, E, so it is a 3rd.
Then add the quality
4ths, 5ths and octaves are perfect; 2nds, 3rds, 6ths and 7ths are major or minor. Squeeze a perfect interval by a semitone and it is diminished; stretch it and it is augmented.
- Minor 3rd = 3 semitones, major 3rd = 4
- Perfect 4th = 5 semitones, tritone = 6, perfect 5th = 7
- Minor 7th = 10 semitones, major 7th = 11
Learn them by ear with songs
Attach a tune to each interval so you can recognise it instantly: a perfect 5th opens Twinkle Twinkle, a major 6th opens My Bonnie, an octave opens Somewhere Over The Rainbow.
Try it
Test yourself