

The first twelve-inch LP (containing only one track per side), was Beethoven's Symphony No. It was marketed initially as being more robust than shellac, with a duration of up to twenty minutes playing time per side. These revolutionary discs were designed for playback at 33 1⁄ 3 rpm (the speed first used on 16‑inch Vitaphone soundtrack discs from 1926) and pressed on ten and twelve-inch diameter flexible Victrolac discs, using a polyvinyl chloride (PVC) compound called vinylite which was licensed from Union Carbide. In August 1931, RCA Victor launched the first commercially available vinyl long-playing record, marketed under their Program Transcription series. Main articles: LP Record § RCA Victor, and Single (music) § 7-inch format These brittle shellac discs remained a popular medium through the first attempt to introduce vinyl records in 1931, the subsequent move towards microgroove formats from 1948, and would survive until the early 1960s. An album would consist of several of these single discs packaged together. During the 1910s discs became the standard sound reproduction format, although the speeds used could vary between manufacturers until 78 rpm became the norm from around 1925. These first twelve-inch releases were all by the Victor Grand Concert Band, led by Frederick W. In 1903 12-inch discs were introduced by Victor, on their Deluxe label, these able to play for up to four minutes, so increasing what were non-achievable times of the length of a song or speech on the earlier formats. Johnson merged their efforts within the industry to form the Victor Talking Machine Company in New Jersey, USA and perfected the use of 5 and 7-inch rotating shellac discs for sound replay from 1889, with 10-inch records appearing in 1901. Gramophone records had been introduced in the latter portion of the 19th century, with several pioneers involved in sound reproduction development such as Thomas Edison and Emilie Berliner. Many record companies in the 1970s began producing 12-inch (30 cm) singles at 33 + 1⁄ 3 rpm, although 45 rpm gives better treble response and was used on many twelve-inch singles, especially in the UK. This extra space permits a broader dynamic range or louder recording level as the grooves' excursions (i.e., the width of the groove waves and distance traveled from side to side by the turntable stylus) can be much greater in amplitude, especially in the bass frequencies important for dance music. Twelve-inch singles typically have much shorter playing time than full-length LPs, and thus require fewer grooves per inch. 2.4.2.7 First wide scale promotional 12".2.4.2.5 Promotion through media and DJs.
