Leftfield are a British electronic duo formed in 1989. They began as the duo of Neil Barnes and Paul Daley (the latter formerly of the Rivals and A Man Called Adam). In January 2010 Barnes resurrected Leftfield without Daley and, after touring for a few years, finished writing new material for a third album titled Alternative Light Source. Daley declined to be involved and is focusing upon his solo career.
The duo was 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 and Fatboy Slim, Leftfield was notable for their use of guest vocalists in their works. Among those involved 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.