C81 was a cassette that was obtained through the British magazine New Musical Express in 1981 (hence (C)assette 81) and released in conjunction with the record label Rough Trade. Intended to mark the first 5 years of the independent label movement in the UK record industry and Rough Trade itself, it was the first in a series of many cassette releases from the paper, including the C86 compilation of 1986. Publishing a tape was also an acknowledgment of the flourishing self published cassette culture of the time that the NME had been supporting in its short lived Garageland column.
C81 was compiled by NME journalist Roy Carr, and Christopher Rose, who worked in public relations for Rough Trade. To get a copy, NME readers had to collect two coupons from the newspaper and send off £1.50. The 15,000 orders were sold out within a month.
The tape contained a set of 25 diverse tracks ranging from jazz (James Blood Ulmer), poetry (John Cooper Clarke), ska (The Beat), and the folksy 'Canterbury Scene' (Robert Wyatt). British music writer Simon Reynolds called it "post punk's swan song", noting the appearance of three acts from Scottish independent label Postcard Records, and the emerging new pop tendency of bands such as Linx and Scritti Politti.