The 12-inch single (often simply called 12") is a type of gramophone record that has wider groove spacing and shorter playing time compared to typical LPs. This allows for louder levels to be cut on the disc by the cutting engineer, which in turn gives a wider dynamic range, and thus better sound quality. This record type is commonly used in disco and dance music genres, where DJs use them to play in discos or clubs. They are played at either 33? or 45 rpm. Technical features 12-inch singles typically have much shorter playing time than full-length LPs, thus require fewer grooves per inch.