Alterations is a British free-improvisation quartet comprising David Toop, Peter Cusack, Terry Day, and Steve Beresford. Formed in 1977, the group remained active until 1986, performing extensively throughout the United Kingdom and mainland Europe. Their music combines free improvisation with an eclectic approach to genre, often incorporating contrasting styles and unconventional musical ideas. The quartet became known for its unpredictable performances and humorous approach to genre conventions, with interactions that could be both collaborative and confrontational. Alterations released three albums during their initial period: Alterations (1978), Up Your Sleeve (1980), and My Favourite Animals (1984). Later releases included Alterations Live (2000) and Voila Enough! (2002).
