This three-CD set may be a memory of a time and place that’s long gone, but what a time and what a place. Down in the cellar of a restaurant in the middle of London, Les Cousins (originally intended to be pronounced in the French way) was one of the crucibles of the British folk scene, playing host to quite a few artists who’d go on to become famous. The club’s all-nighters on the weekend gave musicians chance to develop their skills and be paid for the privilege. People like Bert Jansch, John Renbourn, Sandy Denny, even a pre-pop fame Cat Stevens (Yusuf Islam) and many Americans like Jackson C. Frank and Derroll Adams honed their sound on that stage.

It's very much an acoustic guitar fest, where the folk revival of the 50s met the British blues boom of the early 60s, along with the dawn of the new singer-songwriter age/ It was a time when anything went and the lines between genres were gloriously blurred and messy; a period when a busker and one-man band like Don Partridge could perform, record, and score a surprising hit single (“Rosie”).

The singer-songwriters were a fairly new breed, learning to walk in the wake of Dylan, and still trying to find their voices. So you have John Martyn sounding impossibly twee on “Fairytale Lullaby,” an annoying Al Stewart and some unformed Nick Drake. However, a couple here were on the cusp of great things - Donovan (who first came to prominence in 1965) and Paul Simon, but they were the exception rather than the rule.

Although everyone here put out albums (and there were others, not included because it proved impossible to secure the rights), not all found any real measure of fame and fortune: The Piccadilly Line, for instance, along with Mudge & Clutterbuck and Owen Hand. But it also proved a spawning ground for other things, with Bert Jansch a club regular and playing with John Renbourn (who also performed and recorded with Jacqui McShee before they all morphed into Pentangle).

Cousins gave one-time teen pop hopeful Duffy Power the opportunity to reinvent himself as a powerful, earthy singer. And for those already firmly established, like Davey Graham or the light of the London blues scene, Alexis Korner, it offered a pleasant little gig.

Inevitably, given the era, a little hippieness intrudes, with Ron Geesin offering the wild experimental “Two Fifteen String Guitars For Nice People,” a post-Soft Machine Kevin Ayers with “Eleanor’s Cake (Which Ate Her),” and Ireland’s gleefully bizarre Dr. Strangely Strange leavening the mix.

There’s also a fine sprinkling of traditional music, too, a reminder of the real folk side. Artists like Anne Briggs (performing one of her own compositions, however), Tim Hart and Maddy Prior, Martin Carthy and Dave Swarbrick and others. But among all the strings, it’s the two groups of unaccompanied singers who explode out of the speakers with all the force of a freight train. The Watersons and The Young Tradition are wildly different from each other, but both are a powerful clear tonic of pure sound.