<P> Singles have been issued in various formats, including 7 - inch (18 cm), 10 - inch (25 cm), and 12 - inch (30 cm) vinyl discs (usually playing at 45 rpm); 10 - inch (25 - cm) shellac discs (playing at 78 rpm); cassette, 8 and 12 cm (3 - and 5 - inch) CD singles and 7 - inch (18 cm) plastic flexi discs . Other, less common, formats include singles on digital compact cassette, DVD, and LD, as well as many non-standard sizes of vinyl disc (5 - inch / 12 cm, 8 - inch / 20 cm, etc .). Some artist release singles on records, a trend more common in musical subcultures . </P> <P> The most common form of the vinyl single is the 45 or 7 - inch . The names are derived from its play speed, 45 rpm, and the standard diameter, 7 inches (18 cm). </P> <P> The 7 - inch 45 rpm record was released 31 March 1949 by RCA Victor as a smaller, more durable and higher - fidelity replacement for the 78 rpm shellac discs . The first 45 rpm records were monaural, with recordings on both sides of the disc . As stereo recordings became popular in the 1960s, almost all 45 rpm records were produced in stereo by the early 1970s . Columbia, which had released the 33 1⁄3 rpm 12 - inch vinyl LP in June 1948, also released 33 1⁄3 rpm 7 - inch vinyl singles in March 1949, but they were soon eclipsed by the RCA Victor 45 . The first 45 rpm record created was "PeeWee the Piccolo" RCA Victor 47 - 0146 pressed 7 December 1948 at the Sherman Avenue plant in Indianapolis, R.O. Price, plant manager . The first release of the 45 came March 29, 1949 in seven translucent colors, one for each type of music: dark blue 52 - xxxx light classics series, light blue 51 - xxxx international series, yellow 47 - xxxx juvenile series, bright red (cerise) 50 - xxxx folk series, deep red 49 - xxxx classical series, green (teal) 48 - xxxx country series, and black 47 - xxxx popular series . Except for the 47 series these series started with 0000 . 50 - 0000 (Arthur Crudup), 51 - 0000 (Meisels), 52 - 0000 (Al Goodman) The claim made that 48 - 0001 by Eddy Arnold was the release of the 45 is evidently incorrect (even though as of this writing 48 - 0000 has not turned up) since all 45s were released simultaneously with the 45 player on the March 29th date . There was plenty of information' leaked' to the public about the new 45 rpm system through front page articles in Billboard magazine on Dec. 4, 1948 and again Jan. 8, 1949 . RCA was trying to blunt the lead Columbia had established in releasing their 33 1 / 3 LP system back in June 1948 . </P> <P> Although 7 inches remained the standard size for vinyl singles, 12 - inch singles were introduced for use by DJs in discos in the 1970s . The longer playing time of these singles allowed the inclusion of extended dance mixes of tracks . In addition, the larger surface area of the 12 - inch discs allowed for wider grooves (larger amplitude) and greater separation between grooves, the latter of which results in less cross-talk . Consequently, they "wore" better, and were less susceptible to scratches . The 12 - inch single is still considered a standard format for dance music, though its popularity has declined in recent years . </P>

What year did 45 rpm records come out