Numbered musical notation and so on. Dashes after a note lengthen it, each dash by the length of a quarter note. A dot after the plain or underlined note works increases its length by half, and two dots by three quarters. The underline, along with its joining, are analogous to the number of flags and beaming in standard notation. So are dotted notes. But the analogue stops at notes worth three quarter notes and beyond, where dashes are used instead. The number "0" represents the musical rest. The rules for length is similar to that of the note, except that it is customary
A♭ (musical note) A♭ (musical note) A (A-flat; also called la bémol) is the ninth semitone of the solfège. It lies a diatonic semitone above G and a chromatic semitone below A, thus being enharmonic to G, although in some musical tunings, A will have a different sounding pitch than G. When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the A above middle C (or A) is approximately 415.305 Hz. See pitch (music) for a discussion of historical variations in frequency. A/G is the only note to have only one other enharmonic.