G♯ (musical note)

G♯ (G-sharp) or sol dièse is the ninth semitone of the solfège. In the German pitch nomenclature, it is known as gis.

It lies a chromatic semitone above G and a diatonic semitone below A, thus being enharmonic to la bémol or A♭ (A-flat).

When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the G♯ semitone is approximately 415.305 Hz. See pitch (music) for a discussion of historical variations in frequency.

The notes A♭ and G♯ are the only notes to have only one enharmonic, since they cannot be reached in any other way by a single or double sharp or a single or double flat from any of the seven white notes.