MusicReasonScales, Keys, Intervals, and Notation
What key could these notes belong to?
Select the notes you have. This tool ranks major and natural-minor keys compatible with that set and explains why the input alone cannot establish a unique key — it is not an audio key detector and never infers a tonic from note membership alone.
Answer
Want to learn more? Scales, Modes, and Tonal Centers
Understand
A pitch-class set alone cannot establish a key: it carries no information about which chords actually occurred, in what order, or which note functioned as a resting point. A stated tonic changes the ranking but never rewrites the input's own spelling, and this tool never claims rhythmic or functional evidence it does not have.
Worked example
C, D, E, F, G, A, and B together support both C major and A minor equally, since the two keys share every pitch class. A single note like C alone produces many broad alternatives, since nearly every key's scale contains that one pitch class somewhere.
Method and limitations
The tool compares your selected pitch classes against every major and natural-minor key's own scale, labeling an exact match separately from a superset match that would require additional notes. A stated tonic only reorders candidates that already fit; it cannot promote a key whose scale does not contain your selected notes.
What would actually resolve the ambiguity
Genuinely narrowing a key beyond what a note set alone can show requires evidence this tool deliberately does not have: which chord came first, which note resolved a phrase, or which chord carried a cadence. Those are rhythmic and functional facts, not membership facts, which is exactly why a real analysis of a progression (see Progression Analyzer) can succeed where a bare note list cannot.