Original sentence: Leigh Ashford was a rock group formed in Toronto, Ontario, Canada in 1966 by, guitarist Gord Waszek, vocalist Dave Cairns, bassist Joe Agnello and keyboard player Newton Garwood
Edited sentence: Leigh Ashford was a rock group formed in Toronto, Ontario, Canada and which existed between 1966 and 1974.The group was formed by, guitarist Gord Waszek, vocalist Dave Cairns, bassist Joe Agnello and keyboard player Newton Garwood