Enharmony

Enharmony is a concept in music theory where two or more different written notes represent the same pitch. This occurs within the system of equal temperament, which divides the octave into twelve equal semitones. For example, the note C sharp and the note D flat are played at the exact same frequency on a piano tuned to equal temperament, but they are written differently. Similarly, F double sharp and G natural represent the same pitch.

The primary function of enharmony is to facilitate the understanding and notation of musical passages, particularly those that involve chromaticism or modulations to distant keys. Different enharmonic spellings can clarify the harmonic function of a note or simplify complex accidentals. For instance, in a minor key, the leading tone is often raised, and its enharmonic equivalent might be written to maintain a clearer melodic or harmonic context.

The choice of which enharmonic spelling to use is often dictated by the musical context, including the key signature, the prevailing harmony, and melodic considerations. For instance, a note might be spelled as a sharp in one chord and as a flat in another, even though the physical pitch remains the same. This choice helps musicians interpret the intended harmonic relationships and navigate the score more efficiently. While equal temperament is the most common tuning system in Western music today, the concept of enharmony has roots in older tuning systems as well, though the exact pitches represented by enharmonically equivalent notes could vary.