A four-CD "digibook" of the Mamas and the Papas? Somewhat superfluous, given that you could fit everything you'll ever need from the band on a single disc. Not that this isn't meticulously packaged and annotated, bulging with colour photos and an immense booklet, but it does demonstrate that, although the quartet created a unique vocal sound and a string of hits that will survive long after California has tumbled into the sea, they were a singles band who didn't shine when trying to fill an album-sized hole.

The group began life in 1964 as folk trio the New Journeymen - surely perfect candidates for Christopher Guest's satirical movie about the genre, A Mighty Wind - and became The Mamas & the Papas with the addition of Cass Elliot, whose powerful voice and Wagnerian proportions gave the group much of its character. The glorious California Dreamin' (1966) remains their signature hit, but Monday Monday, Dedicated to the One I Love and the autobiographical Creeque Alley all helped to define a particular strain of west coast folk-pop. However, being more overtly a pop band than the likes of the Byrds or the Buffalo Springfield, the foursome strayed into nightmarish pastures when they were let loose in the studios. They recorded frightful instrumentals and wallowed in atrocious string arrangements, while tunes like String Man are hilariously anachronistic - "The way he moved and looked so groovy/ Well you know he did somethin' to me ..." But virtually every note they recorded is included here, including some solo material and chunks of an album they made with Barry "Eve of Destruction" McGuire, so there's no better place to scrutinise their contribution to pop history.