Music Interval Finder

Use both spelling and sound

Enter the lower and upper pitch exactly, including accidentals and octave numbers. The finder reports direction, interval number, and quality. Number comes from written letter distance: C through E spans three letters, so every kind of C to E is a third. Quality distinguishes C to E natural, a major third, from C to E-flat, a minor third. Counting only piano keys can find semitones, but it cannot by itself preserve the written meaning.

Worked examples across octaves

For C4 to D5, do not reduce the answer to a second if register matters. A ninth affects spacing, hand position, and notation differently from a second. By contrast, interval class can be useful during chord analysis, where ninths and seconds may be treated as related sounds. Decide which description answers the task: exact performed distance or simplified harmonic relationship.

1. Predict the number by counting letters inclusively.
2. Predict whether it sounds stable, tense, wide, or narrow without using a song mnemonic.
3. Check the calculated quality and count semitones only if your prediction differs.
4. Play the pitches separately, then together when the keyboard range allows.

Frequent mistakes include counting the starting note as zero, ignoring enharmonic spelling, and reversing direction. C-sharp to D-flat is written as a diminished second even though they sound on the same piano key; C-sharp to C-sharp is a perfect unison. For a practical drill, create six pairs from one scale: three adjacent notes, two skips, and one pitch in the next octave. Name each interval before checking. If errors cluster around sixths and sevenths, practise those categories rather than repeating every interval equally.