means "lower in pitch." More specifically, in music notation
means "lower in pitch
by a semitone
," and has an associated symbol, which looks like a lowercase "b"; the note A flat
is shown in musical notation
in Figure 1. Under equal temperament
, C flat
is the same as, or enharmonically equivalent to, B
and F flat
is the same as E
There also exist double-flats, which look roughly like "bb" and lower a note by two semitones. Less often one will encounter half, three-quarter, or otherwise altered half.
In musical tuning, flat can also mean "very slightly lower in pitch." If two strings are slightly out of tune, the lower-pitched one is said to be flat with respect to the other.
Figure 1. The note A flat on the treble clef.
See also sharp
♭ may display as a flat sign on some computers.
The word flat also has other, unrelated uses: