Leftfield is a British electronic music group formed by Neil Barnes and Paul Daley. The duo were very influential in the evolution of electronic music in the 1990s, with Mixmag describing them as ‘the single most influential production team working in British dance music’. As with many of their contemporaries, such as the Chemical Brothers, Leftfield were notable for their use of guest vocalists in their electronic music. Among the more prominent were Toni Halliday on ‘Original’, Johnny Rotten on ‘Open Up’, Djum Djum on ‘Afro-Left’, and Earl 16 and Cheshire Cat on ‘Release the Pressure’. The term progressive house was coined to define their style, a fusion of house with dub and reggae.