 "S & M" is an uptempo hi-NRG-Eurodance song that lasts four minutes and three seconds. The song is composed in the key of E-flat minor using common time and a moderate dance tempo of 128 beats per minute. Instrumentation is provided by synthesizers, a keyboard and a guitar. Chris Ryan of MTV described the song as a "steady-rocking dance track, with ominous, snarling keyboard sounds."
