Leftfield are a British electronic music group formed in 1989, a duo of Neil Barnes and Paul Daley. The duo was 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 and Fatboy Slim, Leftfield are notable for their use of guest vocalists in their works. Among them are Toni Halliday on "Original", Johnny Rotten on "Open Up", Djum Djum on "Afro-Left", Earl 16 and Cheshire Cat on "Release the Pressure", and Grian Chatten of Fontaines D.C. on Full Way Round. The term progressive house was coined to define their style, a fusion of house with dub and reggae.