IQ were one of a small number of British bands formed during the early 1980s, including Marillion, Pendragon, Twelfth Night and Pallas, that continued with the progressive rock style forsaken by 1970s bands such as Genesis and Yes. The music press coined the phrase neo-progressive to describe these bands, often accusing them of simply copying the styles of other bands. This accusation has been strenuously denied by IQ, which are against of the use of the term "neo progressive" and claim to have a wide-ranging and eclectic selection of musical influences.
From 1982, the line-up consisted of Peter Nicholls (vocals), Mike Holmes (guitar), Martin Orford (keyboards), Paul Cook (drums), and Tim Esau (bass). Vocalist Peter Nicholls left in 1984 to form a new band, Niadem's Ghost, and was replaced by Paul (P. L.) Menel, but subsequently returned in 1990. Nicholls also created the cover art for most of the albums on which he appears. In early 2005 member Paul Cook left the band, and was replaced on drums by Andy Edwards. On July 20th 2007 Martin Orford announced he was leaving IQ and was replaced by Mark Westworth from prog-rock band Darwin's Radio. Despite his departure, Martin continues to run the band's label GEP and is still closely involved with the band, although he announced in late 2008 that he will leave the music business entirely and hand over the reins of GEP to someone else (as yet unnamed) in early 2009.
The band's musical style, especially earlier in their career, was reminiscent of Peter Gabriel and Steve Hackett era Genesis because of singer Peter Nicholls' vocal and stage-presence similarities to Gabriel and keyboardist Martin Orford's grandiose keyboarding. However, guitarist Mike Holmes' role was far more assertive in the band, giving them a harder edge musically. After Nicholl's departure, the band's style became increasingly commercial and radio-friendly - albeit without much success - on Nomzamo (1987) and Are You Sitting Comfortably? (1989), although each album still featured some progressive rock-style tracks. Beginning with Nicholls's return on 1993's Ever, the band returned to its prog rock roots, with longer tracks featuring intricate arrangements and complex musicianship.