Most observers assumed the story of Pink Floyd had ended nine years ago, on the Live 8 stage in Hyde Park, with an awkward group hug that at least one band member had to be visibly coerced into joining. It was a perfectly Pink Floydish way to end Pink Floyd: ostensibly an act of reconciliation and closure after years of rancour, it still revealed a great deal about the icy British reserve that shrouded the band’s career.

And yet here we are, a decade on, faced with The Endless River, a “new” Pink Floyd album that, on the one hand, isn’t new at all – it’s based on 20-year-old outtakes from sessions for their second post-Roger Waters album, The Division Bell. On the other hand, it sounds more like Pink Floyd – or at least the Pink Floyd who sold 50m copies of The Dark Side of the Moon – than any new album bearing their name in the past 35 years. But why? And why now? There has to be a reason, and it’s obviously not the one that usually motivates bands of a certain vintage to spiff up their studio outtakes, Pink Floyd belonging in the tiny band of artists who clearly never have to do anything for the money. The official line is that it’s intended as a belated tribute to Richard Wright, the keyboard player who died of cancer in 2008. A conspiracy theorist might suggest it’s one final act of niggly passive aggression, ensuring the band’s own final act doesn’t involve their former bassist, a statement that the band’s appeal had more to do with their sound – or rather, Gilmour’s hugely distinctive guitar-playing and Wright’s keyboards – than their erstwhile leader’s doomy lyrical vision. A cynic might also speculate wildly about contractual obligations to their record label.

Whatever the reason, The Endless River offers long-time fans a chance to wallow in a lot of very, very Gilmouresque soloing, heavy on the yearning string-bends and his patented emotional shift from introspective melancholy to soaring euphoria, and to pick their way through series of knowing references to Pink Floyd songs past. At one point, a snatch of the guitar solo from Another Brick in the Wall (Part 2) crops up; and an old recording of Wright playing the pipe organ at the Royal Albert Hall is titled Autumn ’68 in a nod to Summer ’68 on Atom Heart Mother. With their doleful tempi and washes of synth, the beautiful, elegiac opening pairing of Things Left Unsaid and It’s What We Do are clearly intended to evoke the opening moments of the group’s other beautiful elegy for a lost bandmate, Wish You Were Here from 1975. Given Wright’s complicated employment history with the band – sacked during the recording of The Wall, brought back as a salaried session musician for the ensuing tour, shut out of the making of The Final Cut, returning on a weekly wage during the first post-Waters album, A Momentary Lapse of Reason – they could have called it Sign on You Crazy Diamond. Elsewhere, the soft piano chords and sax solo of Anisina are clearly cut from the same cloth as Us and Them, while Sum’s rattling drums and air of mounting tension recalls Nick Mason’s brilliant, rototom-heavy introduction to Time.

Pink Floyd’s The Endless River: a ‘new’ look at old ideas

The big difference is that Nick Mason’s brilliant rototom-heavy introduction to Time leads into, well, Time. Sum, on the other hand, segues into a track called Skins, which turns out to be – oh God – a two-and-a-half-minute drum solo. A band that hits you with a lengthy drum solo barely 15 minutes into an album runs the risk of appearing as if they’re short on ideas and trying to pad things out a bit. The last time Pink Floyd countenanced such a thing was on 1969’s Ummagumma, an album that bore a distinct hint of will-this-do? about it. Very occasionally, you catch a whiff of something similar about The Endless River. There’s obviously a certain wry humour in calling a track off a largely instrumental album based on 20-year-old outtakes On Noodle Street, but there’s also a grain of truth in the title. For all the painstaking sonic detail, the effort clearly put into making it flow, occasionally The Endless River betrays its genesis a little too obviously.

That said, there is a lot of lovely music here and, fittingly, a lot of it is inspired by Wright’s playing. Ebb and Flow, which features Gilmour’s slide guitar winding languidly around a beatific electric piano figure, is particularly gorgeous. There’s something moving about the interplay between Wright’s 45-year-old keyboard part and Gilmour’s latter-day additions on Autumn ’68. It seems to embody the album’s idealistic central theory, that despite the bitterness and the passive-aggressive silences, a deep musical bond exists between members that can’t be broken by lawsuits, bitchy interviews, or perhaps even death. There are also moments when The Endless River sounds like a series of musical prologues strung together, like a spot-the-intro round in a particularly laid-back pub quiz. You listen to something like Anisina and think: this is very nice, but would it have killed you to work it up into a song? It’s compounded by the fact that, the one time they do, it’s pretty great: Louder Than Words is stately, poignant and open-hearted, and the album could use a couple more like it.

But that would have made The Endless River a more substantial album, which is surely the reason why there aren’t a couple more songs on it. People tend to use the phrase “a footnote to their career” in order to damn a record with faint praise, but there’s a sense that a footnote to Pink Floyd’s career may be precisely what The Endless River is supposed to be: not a new album from an extant band, but an echo from the past – or a last, warm but slightly awkward group hug. The one member of the group who declined, or wasn’t invited, to join in might be inclined to disagree, but on those terms, it works just fine.