What is "mastertapes"

Mastertapes is a BBC Radio 4 programme, presented by John Wilson, which discusses the making of significant rock albums. The featured artists are interviewed, in front of an audience, and perform exclusive live tracks, many of which are available on the programme's website. Each album is discussed over two half-hour programmes: the "A side" programme features the artist being interviewed by Wilson, with the "B side" programme featuring questions from the studio audience. The first episode, featuring Billy Bragg discussing his 1986 album Talking with the Taxman about Poetry, was broadcast on 30 Oct 2012. As of December 2014, there have been four series.