As band names go, the Ghost of a Saber Tooth Tiger doesn't seem destined to embody rock immortality. It sounds like a goof. Sean Lennon is self-aware enough to realise that. "Sorry about our name, all the best ones were taken," he says. "The Troggs. Backstreet Boys." As an acronym, though, it does fold up into itself in a pleasing way. The GOASTT are ghosts twice over.

Consciously or not, some of the multi-generational crowd stuffed into this basement venue may have come in search of spirits long departed, and with his long hair, beard and big Terry Pratchett hat, Sean Lennon does currently resemble his father circa 1969. He and Charlotte Kemp Muhl have been songwriting partners (and also a couple) for six years, progressing from sweet acoustic sketches to the psych-rock of their current album, Midnight Sun, a big, crashy record that salutes Sgt Pepper and air-kisses the Flaming Lips.

With Muhl on bass and four capable, boho-looking utility players whipping up wigged-out guitar spirals and organ swirls, the GOASTT create a swampy, forceful sound. Lennon favours a mic that flattens and frazzles his voice. It also gives his between-song badinage about "supernormal stimulation" and Scottish stout a distinctly Dalek edge.

At times, things teeter into pastiche. The minor-key melody of Animals is saved by insistent harmonies, while Poor Paul Getty turns an upsetting true story of kidnapping and ear-mutilation into an oddly jaunty jam. There are lots of extended song bridges, but guitar solos are kept to a minimum.

The son of a famous rock star making retro music with a model – the GOASST could easily be woeful, a privileged, empty exercise in dressing-up-box whimsy. But Lennon and Muhl combine songwriting care and craft with a tangible sense that they're having an absolute blast. Vitally, the audience is invited to share in the fun. The feeling is infectious.

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