Note value Note value In music notation, a note value indicates the relative duration of a note, using the texture or shape of the "note head", the presence or absence of a "stem", and the presence or absence of "flags/beams/hooks/tails". Unmodified note values are fractional powers of two, for example one, one-half, one fourth, etc. A rest indicates a silence of an equivalent duration. The breve appears in several different versions, as shown at right. The first two are commonly used; the third is a stylistic alternative. Sometimes the longa or breve is used to indicate a very long note of indefinite
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.