An EP (short for extended play) is a musical recording that contains more music than a single, but is usually too short to qualify as a full studio album or LP. The term EP originally referred to specific types of vinyl records other than 78 rpm standard play (SP) records and LP records, but it is now applied to mid-length compact discs and music downloads as well. Ricardo Baca of ''The Denver Post'' said, "EPs—originally extended-play 'single' releases that are shorter than traditional albums—have long been popular with punk and indie bands." In the United Kingdom, the Official Chart Company defines a boundary between EP and album classification at 25 minutes of length or four tracks (not counting alternative versions of featured songs, if present).
EPs were released in various sizes in different eras. The earliest multi-track records, issued around 1919 by Grey Gull Records, were vertically cut 78 rpm discs known as "2-in-1" records. These had finer than usual grooves, like Edison Disc Records. By 1949, when the 45 rpm single and 33 rpm LP were competing formats, seven-inch 45 rpm singles had a maximum playing time of only about four minutes per side.
Partly as an attempt to compete with the LP, introduced in 1948 by rival Columbia Records, RCA Victor introduced "Extended Play" 45s during 1952. Their narrower grooves, achieved by lowering the cutting levels and, if required, sound compression, enabled them to hold up to 7.5 minutes per side—but still be played by a standard 45 rpm phonograph. These were usually 10-inch LPs (released until the mid-1950s) split onto two seven-inch EPs or 12-inch LPs split onto three seven-inch EPs, either sold separately or together in gatefold covers. This practice became much less common with the advent of triple-speed-available phonographs.
Some classical music albums released at the beginning of the LP era were also distributed as EP albums—notably the seven operas that Arturo Toscanini conducted on radio between 1944 and 1954. These opera EPs, originally broadcast on the NBC Radio network and manufactured by RCA, which owned the NBC network then, were made available both in 45 rpm and 33 rpm. In the 1990s, they began appearing on compact discs. RCA also had success in the format with their top money earner, Elvis Presley, issuing 28 Elvis EPs between 1956 and 1967, many of which topped the separate ''Billboard'' EP chart during its brief existence.
During the 1950s, RCA published several EP albums of Walt Disney movies, containing both the story and the songs. These usually featured the original casts of actors and actresses. Each album contained two seven-inch records, plus a fully illustrated booklet containing the text of the recording, so that children could follow along by reading. Some of the titles included ''Snow White and the Seven Dwarfs'' (1937), ''Pinocchio'' (1940), and what was then a recent release, the movie version of ''20,000 Leagues Under the Sea'' that was presented in 1954. The recording and publishing of ''20,000 Leagues Under the Sea'' was an unusual one: it did not employ the movie's cast, and years later, a 12-inch 33⅓ rpm album of the film, with a nearly identical script, but another different cast, was sold by Disneyland Records in conjunction with the re-release of the movie in 1963.
Because of the popularity of other formats, SP records became less popular and the production of SPs in Japan was suspended in 1963.
In the 1950s and 1960s, EPs were usually compilations of singles or album samplers and were typically played at 45 rpm on seven-inch (18 cm) discs, with two songs on each side.〔〔
Other than those published by RCA, EPs were relatively uncommon in the United States and Canada, but they were widely sold in the United Kingdom, and in some other European countries, during the 1950s and 1960s. ''Record Retailer'' printed the first EP chart in 1960. The ''New Musical Express'' (''NME''), ''Melody Maker'', ''Disc and Music Echo'' and the ''Record Mirror'' continued to list EPs on their respective singles charts. The Beatles' ''Twist and Shout'' outsold most singles for some weeks in 1963. When the BBC and ''Record Retailer'' commissioned the British Market Research Bureau (BMRB) to compile a chart it was restricted to singles and EPs disappeared from the listings.
In the Philippines, seven-inch EPs marketed as "mini-LPs" (but distinctly different from the mini-LPs of the 1980s) were introduced in 1970, with tracks selected from an album and packaging resembling the album they were taken from. This mini-LP format also became popular in America in the early 1970s for promotional releases, and also for use in jukeboxes.
Stevie Wonder included a bonus four-song EP with his double LP ''Songs in the Key of Life'' in 1976. During the 1970s and 1980s, there was less standardization and EPs were made on seven-inch (18 cm), 10-inch (25 cm) or 12-inch (30 cm) discs running either 33 or 45 rpm. Some novelty EPs used odd shapes and colors, and a few of them were picture discs.
Alice in Chains was the first band to ever have an EP reach number one on the ''Billboard'' album chart. Its EP, ''Jar of Flies'', was published on January 25, 1994. In 2004, Linkin Park and Jay-Z's collaboration EP, ''Collision Course'', was the next to reach the number one spot after Alice in Chains. In 2010, the cast of the television series ''Glee'' became the first artist to have two EPs reach number one, with ''Glee: The Music, The Power of Madonna'' on the week of May 8, 2010, and ''Glee: The Music, Journey to Regionals'' on the week of June 26, 2010.
In 2010, Warner Bros. Records revived the format with their "Six-Pak" offering of six songs on a compact disc.
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