David Crosby (formerly of The Byrds) and Graham Nash (formerly of The Hollies) had first linked up in 1968 in something of an ad hoc group with Stephen Stills, later adding Neil Young and becoming one of the first of the so called supergroups assembled at the end of the decade. Although all four made a number of tours over the next few years, Stills and Young invariably concentrated on other projects and the duo of Crosby and Nash kept the name alive in the ensuing years. Concerts by Crosby and Nash would sometimes see Stills or Young make the occasional guest appearance, prompting hope that the original four might eventually reunite. In the event it is Crosby and Nash that have proved the most durable, as this recording confirms.