SAMPLED

Music theory basics · updated 2026-08-16

INTERVAL

The distance between two pitches, counted in scale steps (a third, a fifth) or in semitones (4, 7).

Photograph of a printed score of Mozart's Rondo alla Turca open on a music desk, showing staves, key signature and note heads — the written notation this section defines.
Music theory basics — Photograph of a printed score of Mozart's Rondo alla Turca open on a music desk, showing staves, key signature and note heads — the written notation this section defines.

Photo: Music Sheet, Mozart's Alla Turca (opens in a new tab) by Schiller12 (opens in a new tab), via Wikimedia Commons — CC BY-SA 4.0 (opens in a new tab)

Key takeaways

  • The distance between two pitches, counted in scale steps (a third, a fifth) or in semitones (4, 7).
  • Counting in semitones is unambiguous and translates directly to MIDI note numbers; counting in scale degrees tells you how the interval will function inside a key.
  • A perfect fifth is seven semitones.
  • Watch out: mixing up interval quality and size.
  • Sits under music theory basics in this glossary, with 2 primary sources below.

Quick checklist

  • Can you define interval in one sentence without looking?
  • Can you point at interval in a real session, mix or contract?
  • Have you tried the practical move above at least once?
  • Would you catch the common mistake before it costs you a take?
  • Have you opened one of the primary sources below rather than a forum thread?

INTERVAL IN DEPTH

Intervals are the unit of measurement for everything else in harmony — chords are stacked intervals, melodies are walked intervals, and voice leading is the study of which intervals move where. Counting in semitones is unambiguous and translates directly to MIDI note numbers; counting in scale degrees tells you how the interval will function inside a key.

How it works in practice

A perfect fifth is seven semitones. In a DAW, transposing a MIDI clip by +7 gives you an instant fifth harmony under a lead line.

The mistake people make

Mixing up interval quality and size. A third can be major (4 semitones) or minor (3), and calling both 'a third' hides the difference that decides whether a chord sounds bright or dark.

WHERE INTERVAL SITS

Interval belongs to music theory basics in the Sampled music glossary. The vocabulary you need before anyone can explain a chart, a chord chart, or a session to you.

TERMS THAT DEPEND ON INTERVAL

  • Transposition

    Moving a whole part up or down by a fixed interval, keeping the relationships between notes intact.

  • Octave

    The interval between one pitch and another at double or half its frequency. The two notes share a name because the ear hears them as the same pitch class.

  • Equal temperament

    The tuning system that splits the octave into twelve equal semitones so every key sounds usable, at the cost of pure intervals.

  • Just intonation

    Tuning built from small whole-number frequency ratios. Intervals beat less, but the tuning only works cleanly in a limited set of keys.

TEST YOURSELF

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3 quick questions on interval. Answers are marked instantly — nothing is sent anywhere.

  1. 1. Which statement best describes interval?

  2. 2. What is the mistake people most often make with interval?

  3. 3. In practice, which of these applies to interval?

Ready for the full thing? Take the 25-question terminology test and get a certificate with your name and score.

SOURCES AND CITATIONS

Free, primary references for interval — standards bodies, manufacturers, government offices and university course material. Each one lists the line of this entry it backs up.

  • musictheory.net — intervals (opens in a new tab)

    Free interactive lessons · musictheory.net

    “The distance between two pitches, counted in scale steps (a third, a fifth) or in semitones (4, 7).”— the claim this source supports

    Why it counts: Short interactive drills that let you test the concept immediately rather than only read about it.

  • Open Music Theory — intervals (opens in a new tab)

    Open textbook · Open Music Theory

    “Intervals are the unit of measurement for everything else in harmony — chords are stacked intervals, melodies are walked intervals, and voice leading is the study of which intervals move where.”— the claim this source supports

    Why it counts: An openly licensed university textbook, so the definition can be checked against a citable academic source.

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