(1) An extent along the frequency dimension in which a signal exists is the band. For instance, an octave band is one octave wide. The AF band is 20Hz-20kHz wide. (2) The wider spiraled grooves that separate any two selections on a record. (3) Band is also used to indicate any single selection on a record, cassette, or reel-to-reel tape or CD, i.e., a track.