A maxi single or maxi-single (sometimes abbreviated to MCD or CDM) is a music single release with more than the usual two tracks of an A-side song and a B-side song.

The first maxi singles

The term came into wide use in the 1970s, where it usually referred to 7-inch vinyl singles featuring one track on the A-side and two on the B-side. The 1975 reissue of David Bowie's "Space Oddity", where the featured song is coupled with "Changes" and "Velvet Goldmine", is a typical example. By the mid-1970s, it was used to refer to 12" vinyl singles with three or four tracks (or an extended or remixed version of the lead single/song) on the A-side, with an additional two or three tracks on the B-side; the B-side would initially be used by DJs. Later, in the 1980s, a typical practice was to release a two-song single on 7" vinyl and cassette, and a maxi-single on 12" vinyl.

These first 12" maxi-singles were promotional and mostly sent to discotheques and radio stations. Examples of such promos—released at almost same time in 1975—are Gary Toms Empire  – "Drive My Car", Don Downing – "Dream World", Barrabas – "Mellow Blow", The Trammps – "Hooked for Life", Ace Spectrum – "Keep Holdin' On", South Shore Commission – "Train Called Freedom", The Chequers – "Undecided Love", Ernie Rush – "Breakaway", Ralph Carter – "When You're Young and in Love", Michael Zager & The Moon Band Feat. Peabo Bryson – "Do It with Feeling", Monday After – "Merry-Go-Round", The Ritchie Family – "I Want to Dance" and Frankie Valli – "Swearin' to God".