Enharmonic Equivalent

Two notes are enharmonic equivalent in 12-TET if they share the same pitch or pitch class, but have different note names.

Here are all of the twelve pitch classes listed with their enharmonic-equivalent names:

0. C (or B♯ or D♭♭)
1. C♯ or D♭
2. D (or C or E♭♭)
3. D♯ or E♭
4. E (or D or F♭)
5. F (or E♯ or G♭♭)
6. F♯ or G♭
7. G (or F or A♭♭)
8. G♯ or A♭
9. A (or G or B♭♭)
10. (or t for ten). A♯ or B♭
11. (or e for eleven). B (or A or C♭)

Chords, scales, or keys can also be enharmonic-equivalent if their notes are enharmonic, for example the Key of F# Major and the Key of G♭ Major.

See Staff Notation for more on why a single pitch class has multiple names.