Born out of jazz and killed off by the punk movement, progressive rock spawned numerous mind-altering album sleeves and was the catalyst for stadium-rock pomposity. John Aizlewood investigates the phenomenon known as "prog rock" and asks why such a disparate group of bands were pigeon-holed as "prog" when their influences actually incorporated styles as diverse as classical, jazz, folk and blues. Among those contributing to the programme are former prog rock musicians Keith Emerson ,
Ian Anderson , Dave Brock and Fish. Producer Phil Ward-Large