Delerium has existed since 1987 as a two-person project led by Vancouver-based electronic music composer and synth player Bill Leeb. Initially Leeb teamed up with Michael Balch who had been a co-collaborator on previous project Front Line Assembly. Since its inception, Leeb has been the only constant in Delerium, working at different times with Balch, Chris Peterson and latterly with Rhys Fulber, another Vancouver based electronic artist. The band's most successful release to date has been the single Silence which went to number one in the Irish charts and number six in Australia. Featuring Sarah McLachlan on vocals, Silence has been acclaimed as one of the greatest trance songs of all time. It marked a change in style and tempo for Delerium and has helped Leeb to cross genres and gain mainstream acceptance by being listed on mainstream radio station playlists. With 15 album releases spanning a 30-year career Leeb's Delerium project remains one of the more enduring of electronic genre recording artists.