A♯

Noun.  A musical note that lies a chromatic semitone above A and a diatonic semitone below B, thus being enharmonic to B♭; the eleventh semitone of the solfege; when calculated in equal temperament with a reference of A above middle C as 440 hertz, it has a frequency of approximately 466.164 Hz.

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.