Music Intervals Explained: Complete Chart & Guide
An interval is the distance between two notes. It's the fundamental unit of music theory — every scale, chord, and melody is built from intervals. Understanding them unlocks everything else.
What is a music interval?
An interval measures the pitch distance between two notes. You can express it two ways: by the number of semitones (half-steps) between the notes, or by its traditional name (major third, perfect fifth, etc.). Both describe the same thing.
Intervals apply to all instruments. On a piano, one semitone = one key (white or black). On a guitar, one semitone = one fret.
When two notes sound at the same time, the interval is called harmonic. When one follows the other, it's melodic. The name and number of semitones is the same either way.
Complete interval chart
| Semitones | Interval name | Abbreviation | Example (from C) | Sound quality |
|---|---|---|---|---|
| 0 | Perfect unison | P1 | C → C | Same note |
| 1 | Minor second | m2 | C → D♭ | Very dissonant, tense |
| 2 | Major second | M2 | C → D | Mild dissonance, stepwise |
| 3 | Minor third | m3 | C → E♭ | Dark, melancholic |
| 4 | Major third | M3 | C → E | Bright, cheerful |
| 5 | Perfect fourth | P4 | C → F | Open, stable |
| 6 | Tritone (aug. 4th / dim. 5th) | TT | C → F♯ | Very tense, unstable |
| 7 | Perfect fifth | P5 | C → G | Hollow, powerful, stable |
| 8 | Minor sixth | m6 | C → A♭ | Bittersweet |
| 9 | Major sixth | M6 | C → A | Warm, pleasant |
| 10 | Minor seventh | m7 | C → B♭ | Tense, bluesy |
| 11 | Major seventh | M7 | C → B | Lush, slightly tense |
| 12 | Perfect octave | P8 | C → C' | Same note, doubled |
Perfect, major, and minor intervals
The terms "perfect," "major," and "minor" describe the quality of an interval, not just its size.
Perfect intervals (unison, fourth, fifth, octave) don't have major/minor versions in standard usage. They're called "perfect" because they sound acoustically pure — the frequency ratios are simple whole numbers. Alter a perfect interval by a semitone and it becomes "augmented" (one semitone larger) or "diminished" (one semitone smaller).
Major and minor intervals come in pairs. A major interval is one semitone larger than its minor equivalent. Flatten a major second and you get a minor second. Flatten a major third and you get a minor third — which is the difference between a major and minor chord.
Why intervals matter: chords and scales
Every chord is defined entirely by its intervals from the root note. A major chord is always: root + major third (4 semitones) + perfect fifth (7 semitones). Change the major third to a minor third (3 semitones) and you get a minor chord. Add a minor seventh (10 semitones) and you get a dominant 7th chord. The chord formula is just a list of intervals.
Scales work the same way. The major scale = 2, 2, 1, 2, 2, 2, 1 (intervals between consecutive notes in semitones). The natural minor = 2, 1, 2, 2, 1, 2, 2. Memorise the interval pattern, and you can build the scale from any starting note.
Consonance and dissonance
Intervals range from very consonant (smooth, stable, "at rest") to very dissonant (tense, unstable, wanting to move). The perfect fifth is the most consonant interval after the unison and octave — it's why power chords in rock sound so solid. The tritone is the most dissonant — it's used in horror music and jazz to create maximum tension.
Most tonal music works by creating tension with dissonant intervals and then resolving to consonant ones. Understanding which intervals are tense (m2, M7, TT) and which are stable (P5, P4, M3) helps you understand why melodies and chord progressions move the way they do.
Ear training: how to recognise intervals
A classic technique is to associate each interval with a familiar melody that starts with that interval:
| Interval | Ascending mnemonic |
|---|---|
| Minor second (m2) | "Jaws" theme |
| Major second (M2) | "Happy Birthday" (first two notes) |
| Minor third (m3) | "Smoke on the Water" riff |
| Major third (M3) | "When the Saints Go Marching In" |
| Perfect fourth (P4) | "Here Comes the Bride" |
| Tritone (TT) | "The Simpsons" theme |
| Perfect fifth (P5) | "Star Wars" main theme |
| Major sixth (M6) | "My Bonnie Lies Over the Ocean" |
| Minor seventh (m7) | "Somewhere" (West Side Story) |
| Major seventh (M7) | "Take On Me" chorus |
| Octave (P8) | "Somewhere Over the Rainbow" |
Practise identifying intervals with the MusoKit ear trainer — it plays two notes and asks you to name the interval, tracking your accuracy over time.
Train your ears on intervals
The ear trainer plays intervals and chord types and tests your recognition. Streak-based, mobile-friendly.
Open Ear Trainer →