That Frank Zappa is a major figure deserving of constant attention is a given. Whether or not we need quite so forensic an exhumation of his music is quite a different question.

Moreover, this ‘Vaudeville’ version of the band with Flo & Eddie's pastiche vox to the fore is of curious, if not dubious, taste. Much was made at the time of Zappa's campaign for free speech, which would culminate in the infamous, and at times hilarious, 1985 obscenity trial. The live recordings capture much of this tension as Zappa and band comply and challenge statements of vulgarity, loyalty oaths and other bureaucratic paraphernalia. It's just a shame that the wit and resilience Zappa shows in the backstage out takes are not reflected in the material. While Zappa claims here that ‘this is not obscene, pornographic’, the likes of ‘What Road Ladies Do to You’ now sound exploitative and in a post-#MeToo age, somewhat dodgy ground on which to argue an important principle.

You'd like to concentrate on the music, but the main extended pieces here are repeated takes of the mighty ‘King Kong’ with Dunbar always impressing, Duke's organ always pleasing (tee hee: see what Zappa encourages). But there are few intimations of the more jazz-driven instrumentals that the later 1970s would bring, although the previously unheard ‘Portuguese Fenders’ has a furious Frank solo on board.

In addition, although it's intriguing to hear a band at work in the studio – the contrast between Zappa's imperious certainty and newbie engineer's Roy Thomas Baker polite Englishness are fun to eavesdrop on – there may be a reason why this material has lain unheard for so long. Go figure.

The three live CDs again have their moments, but several concerts are edited together in an attempt to create an ersatz ‘performance’ experience. Is that really necessary? What's more, the recordings are mainly from Zappa's personal Uher tape recorder so constantly spool out after a few minutes – a case of musical coitus interruptus which Flo and Eddie can giggle over. It says something when the wryest moment among 70 cuts and four CDs is a forlorn Frank getting mistaken for Tiny Tim in a hotel lobby….