Interval
The distance between two notes, measured both in scale degrees and in semitones
Related
An interval is the distance between two notes, and it takes two rulers to measure it. Degree counts how many note names the two ends span (C to E is C–D–E, a third); size in semitones counts the half steps between them (C to E is four). The same degree can come in different widths — C–E is a major third (four semitones), D–F a minor third (three) — which is exactly where major and minor intervals come from.
The usual mistake is to count only semitones or only note names. What the ear hears as a leap is the semitone count; what the score writes is the degree. You need both to describe one interval. Add one more note and it becomes a chord.
Read deeper → Interval
Sources
- 度数首尾俱计、音数按半音计，为通行乐理定义（参 The New Grove Dictionary of Music and Musicians, "Interval"）；本文为原创表述
Used for fact-checking only; all prose is original.