[en-hahr-mon-ik] 
| having the same pitch in the tempered scale but written in different notation, as G sharp and A flat. |
| en·har·mon·ic (ěn'här-mŏn'ĭk) adj. Music Of, relating to, or involving tones that are identical in pitch but are written differently according to the key in which they occur, as C sharp and D flat, for example. [Late Latin enharmonicus, from Greek enarmonios : en-, in; see en-2 + harmoniā, harmony; see harmony.] en'har·mon'i·cal·ly adv. |
enharmonic
in the system of equal temperament tuning used on keyboard instruments, two tones that sound the same but are notated (spelled) differently. Pitches such as F and G are said to be enharmonic equivalents; both are sounded with the same key on a keyboard instrument. The same is true of intervals, which are always named according to their notation: A-F is an augmented sixth, while A-G and G-F are both minor sevenths; all are enharmonically equivalent. C major (which has a key signature with seven sharps) and D major (with five flats) are enharmonically the same key; D major is considered easier to read and thus is much more commonly used than C major. Enharmonic tones and intervals are often components of pivot chords in modulation (change of key), especially if the composer is changing from a key notated in flats to one notated in sharps (or vice versa).
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hɑrˈmɒn