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
Mungo Jerry's first single, "In the Summertime" was the first maxi single in the world. 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 was initially 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 the 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 Bush "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".
Salsoul Records made 12" maxi-singles commercially available for the first time in May 1976 with the release of "Ten Percent" by Double Exposure (SALSOUL 12D-2008). An earlier 12" catalog number from this label is "More" by Carol Williams (SALSOUL 12D-2006), but it was released later.
Cassette maxi singles
Occasionally, a cassette single was released in two cassette formats simultaneously: a traditional Cassette single with two tracks and a cassette maxi-single with four or more tracks, generally remixes. This practice was experimented with in the 1980s.
Example: Debbie Gibson – Out Of The Blue (cassette maxi-single) released by Atlantic in 1987 in the USA. Includes four mixes: 1. Club Mix, 2. Bonus Beats, 3. Drumapella, 4. Dub version. This was packaged in a 12" × 3" cassette maxi single longbox (with a regular cardboard slipcase/cassette inside), although most later maxi singles were just issued in regular style cassette cases.
CD maxi singles
When CDs began to appear as a popular single format in the early 1990s (see CD single), songs were occasionally released in two CD formats simultaneously, 3" and 5", predominantly as a marketing ploy but potentially as a logical extension of the 7" and 12" vinyl record formats to CD, with the 5" CD sometimes marketed as a "maxi-single", most commonly in the US, and European countries (outside of the UK). While the 5" CD version occasionally had additional or longer track mixes, the track listing was often identical.
By the mid 1990s CDs had clearly become the music format of choice. As the 1990s progressed, nearly every single release was available on CD, and vinyl and cassette single releases gradually became less common.
The UK became a thriving market for CD singles, but in 1998 the UK Chart Supervisory Committee reduced the maximal playing time of chart-eligible CD singles from 40 minutes to 20 minutes, though 12" vinyl singles could still play for up to 40 minutes. While Maxi-CDs had been much loved among the dance community, as most if not all of the remixes that had been commissioned by the label could be released commercially, lobbying by artists in other genres who felt obliged to record extra and cover tracks to provide enough material for their single releases was responsible for the rule change. As a result, the U.K.'s singles from around mid-1998 often appeared as three separately-sold CDs with three tracks each, or more commonly, two CDs and an extra format (such as 7", 12" or DVD single). Very often, at least one track was common to all formats. Single releases in the US and elsewhere still included many tracks (primarily remixes) and called themselves maxi-singles to differentiate from the three-track UK versions.
Example: Saint Etienne "Who Do You Think You Are?" (US CD single) Released by Warner Music in 1993 in the USA. Includes eight different tracks, six of which are versions of the title song. Digipak packaging. Labeled "compact disc maxi-single" on the front cover.