In many ways, it was unlikely that Cream would last as long as they did. By the time they split in November 1968, the group had been going for just over two years and recorded four albums. Before then Eric Clapton had cycled rapidly through the Yardbirds and the Bluesbreakers, racking up a few months in each as well spending time in shorter one-off projects like The Immediate All-Stars and The Powerhouse, while Jack Bruce and Ginger Baker were famed for their incendiary relationship in the Graham Bond Organisation.

In that context, Cream were stayers. When they inevitably decided to split, their autumn US shows were renamed the Goodbye Tour and the band signed off with two sets at the Royal Albert Hall. Four entire shows – Oakland, LA, San Diego and London – from this arrivederci have now been collected on Goodbye Tour – Live 1968, including the band’s last show at the Royal Albert Hall, where an unemotional departure is concluded by compere John Peel’s matter-of-fact last words: “That really has to be it.”

The Royal Albert Hall show was previously available on VHS and DVD – this is the first time it’s appeared on CD. Sadly the sound hasn’t improved a great deal in this transfer. It’s the muddiest of the four, at times sounding like it was recorded in the bottom of an empty swimming pool. Fortunately, the other three shows sound pretty good, with San Diego probably the pick of the lot. Of the 36 tracks, 19 are previously unreleased. Three tracks from LA – “I’m So Glad”, “Politician” and “Sitting On Top Of The World” – appeared on Cream’s studio-live hybrid swansong Goodbye, while three from Oakland – “Deserted Cities Of The Heart”, “White Room” and “Politician” – were on 1972’s Live Cream Volume II. LA’s staggering 17-minute finale of “Spoonful” features on the soundtrack album Eric Clapton: Life In 12 Bars.

“Spoonful” features in every show, invariably in extended, improvised versions, almost unrecognisable from the haunting take recorded for Fresh Cream, let alone Willie Dixon’s original. “I’m So Glad” also gets strung out into double-digit minutes, while “Toad” features an arduous Ginger Baker drum solo – although on the opening night of the tour in Oakland this workout took place during “Passing The Time”. These lengthy improvisations and the band’s sheer muscle are what made them such a formidable live proposition. If there are occasions when the rugged soloing gets a little bogged down in detail, there are many others where the trio achieve moments of adrenalising magic, like five minutes into San Diego’s version of “Spoonful” when Baker suddenly hastens the beat and coaxes Bruce and Clapton into ever wilder, faster and exceptionally groovy patterns of playing.

Cream aren’t the most graceful of bands but they go about their business with a serious, murderous deliberation. It’s impossible to avoid comparisons with the era’s other great psychedelic three-piece, the Experience, who approached things with a tad more elegance and humour, and in Hendrix featured a more accomplished, emotive vocalist. But the sheer systematic fury cooked up by Cream on something like the Albert Hall’s “I’m So Glad” is beautiful to behold, with Clapton firing off incessant volleys to accompany the pulsating rhythm. You can hear hard rock emerging by the bar on the thundering, sinister run through “Sunshine Of Your Love” in San Diego; Led Zeppelin would pick up this mantle and run with it. Hendrix would admire the versatility of “Sunshine…” and cover it throughout his career, slyly acknowledging in the process that the song was written by Jack Bruce after attending an Experience concert in 1967.

The boxset certainly shows how some songs were performed differently during the tour, most notably “Crossroads”. In Oakland it’s played as a slow, churning, moody blues. Two weeks later in LA and San Diego it’s mutated into something more frantic and far sharper, played so fast it’s like a Yardbirds raver. In San Diego it’s paired with a terrific nine-minute ramble through “Traintime”, with Bruce delivering a brilliant display on the harmonica, coaxing a fantastic range of rhythms and sounds from the instrument while Baker’s drumbeat jogs along in support. Given the pair’s mutual antagonism, it’s a moment of joyful synchronicity and shows why they kept working together despite everything.

The San Diego show is beautifully paced, making it the standout gig here. Perhaps that’s because it comes almost exactly midway through the US tour, which started on October 4 in Oakland and ended on November 4 in Providence, Rhode Island – the Royal Albert Hall show came another three weeks later. The San Diego concert, however, took place on October 20, the day after the LA concert at the Forum. It starts with a belligerent, hypnotic “White Room” followed by the cynical “Politician”, two songs written by the Jack Bruce/Pete Brown combination for that year’s Wheels Of Fire album. “I’m So Glad” goes all the way back to Fresh Cream, but whereas that LP cover of the Skip James song is fast, tidy blues-pop with a showy middle section, the live version is relentless, Clapton building up punishing layers of distorted notes supplemented by Hendrix-style flicks while Baker powers it along. It’s not quite as woolly but every bit the equal of the nine-minute version from LA.

The slow, sloping country blues “Sitting On Top Of The World” is beautifully played, steady but prowling for the most part but then suddenly exploding into some frantic soloing from Clapton, and with a vocal in San Diego that’s markedly better than the one from LA released on Goodbye. San Diego’s “Sitting…” leads into a slamming and short “Sunshine…” but ends with the twin excess of “Toad” and “Spoonful”. After Clapton’s “I’m So Glad” and Bruce’s “Traintime”, “Toad” is Ginger’s chance to get some attention, and while the drum solos can be heavy-going in their early sections, the climaxes are always wildly enjoyable, leaving you wondering whether Baker was born with an extra arm. Admiration is topped up by a sense of anticipation as you wait to see how the other two members of the band will combine to bring the song in for landing; “Spoonful”, meanwhile, lets the band spin things out for as long as required at the end of the show.

The exception is the Royal Albert Hall, where the band are less given to improvisation, possibly because they were less familiar with the British audience than they were their American fanbase. Instead they closed their career with “Steppin’ Out”, a song that Clapton recorded both with the Powerhouse and Bluesbreakers as well as at the BBC with Cream. It’s an instrumental, which allows the trio to just get down to the business of playing – and that’s all Cream really wanted to do.

The applause as they leave the stage cuts through the sonic murk, but as a final show it’s strangely muted. For Cream, this tour might have been their farewell but for the most part it was also business as usual, and there are few concessions to nostalgia or sentiment. The one exception comes at the start of the LA show, where Buddy Miles is wheeled on stage to introduce the band – aka “three really out-of-sight groovy cats”. He continues, “What can you say, it’s happened and we can’t do anything about it, but just remember they’ll still be there, and they’ll always be there.” And then without further ado, Cream get back to work with methodical intent.