The Minor 7th Interval (m7)
An interval is the distance between two notes, counted in semitones. Each of the thirteen simple intervals has its own page: reference songs that open with it, where it sits on the guitar fretboard, its inversion, and the chords built from it.
- The Unison (P1) — 0 semitones
- The Minor 2nd (m2) — 1 semitone
- The Major 2nd (M2) — 2 semitones
- The Minor 3rd (m3) — 3 semitones
- The Major 3rd (M3) — 4 semitones
- The Perfect 4th (P4) — 5 semitones
- The Tritone (TT) — 6 semitones
- The Perfect 5th (P5) — 7 semitones
- The Minor 6th (m6) — 8 semitones
- The Major 6th (M6) — 9 semitones
- The Minor 7th (m7) — 10 semitones
- The Major 7th (M7) — 11 semitones
- The Octave (P8) — 12 semitones
The minor 7th spans 10 semitones — a yearning leap that wants to resolve. It does not land on a major-scale degree from the tonic, which is exactly why it sounds so colorful — it lives outside the key. Inverted (the lower note moved up an octave) it becomes the major 2nd.
The classic way to internalize it: sing a song that opens with it — Somewhere (West Side Story) (the leap on "Some-where"); Star Trek (original series theme) (the first big leap). You also hear the minor 7th inside chords built on it, like 7, m7, 7sus4, 9. Then drill it on the ear trainer until you name it without thinking.