Enharmonic refers to the musical phenomenon where two notes are notated differently but represent the exact same pitch frequency within the equal temperament tuning system commonly used today. A classic example is C sharp and D flat; while they are played on the same physical key on a synthesizer or piano, the choice of which name to use is dictated by the harmonic context and the key signature of the piece to ensure correct musical spelling. However, the term holds a deeper meaning in non-equal temperaments, such as Just Intonation or historic Meantone temperaments. In these systems, an enharmonic pair like G sharp and A flat are not identical frequencies but are separated by a minute pitch difference known as a comma, which can be audible and affect the color of chords.