Before glam rock and punk rock hit the UK mainstream in the early to mid-1970s, it was either pop music for the kids or prog-rock for their elder siblings, the post-Beatles/post-psychedelic generation whose music tastes were catered for not just by college/university live music circuits but also by the emergence of open-air events (not least the 1970 Isle of Wight Festival).

Back then, fusion – jazz, blues, classical, rock, folk, anything except pop music – was the name of the game; it was a malleable format that within several years would be bludgeoned to death by the likes of Roxy Music, David Bowie and quite a few sulky punk bands.

That’s the condensed history, but, as with every music movement, there are exceptions to the rule. Questions, too, such as why Van Der Graaf Generator’s prog/folk tune Refugees sounds brilliant, why Hawkwind’s Hurry on Sundown is a lost acoustic-psych classic, and why Kevin Ayers’s Singing a Song in the Morning is a dead ringer for Beck’s early work.

Several tracks stretch the patience. Caravan's Can't Be Long Now unfortunately is, and two Yes songs (Astral Traveller and No Opportunity Necessary, No Experience Needed) are just horrendous. Music preferences aside, there's plenty here to occupy inquisitive minds, not least the accompanying booklet, which is a treasure trove of detailed information about each act. cherryred.co.uk