DJ Shadow, Astoria, London

Shadow of a doubt

Six years after Josh Davis released his ground-breaking collage classic Endtroducing..., the Astoria is packed to bursting-point with a crowd keen to pay respect to a man who raised sampling to an art form. Davis attracts a studious crowd; at one point, a joke is doing the rounds that you need five hands to appreciate the show. Two to applaud every time he makes a "dope" break, two more to text your friend at a Hoxton coffee bar about how good it was and one extra to stroke your beard in contemplation.

A music obsessive who uses his vast but closely guarded CD and vinyl collection to carve beat-obsessed sonic sculptures, Davis comes across as a slightly fey Californian when he's not cueing up the discs. He repeatedly tells the audience how much he loves them and how good it feels to be loved in return. Far out, man.

The show commences with a 12-minute film made by his film-director pal B+. A documentary dedicated to and featuring some of the drumming legends who have fuelled the Shadow sound, the piece is well intentioned but doesn't carry across the venue; the subtitles are too small too read, the sound rendered indecipherable.

The screens are used to much better effect when Shadow takes the stage. The visuals (the TV cast of M*A*S*H listening to an old Dansette; a journey through the galaxy that zeroes in on a needle in a groove) bring to life the unspoken theory that underpins his work. The DJ as sound-curator, the man who can capture the pulse and rhythm of modern life and the universe at large.

Shadow stresses that tracks from his classic debut and the eagerly awaited follow-up, The Private Press, are being reworked for the live show. "Otherwise it would be like playing a record, and you can all do that at home." The sound-as-weapon-salvo of "Walkie Talkie" is appropriately reconfigured in line with an animated cut-up of a Richard Nixon lookalike alternately brandishing a sound-box and a chainsaw. Shadow uses the beat as a foundation for expansive explorations, too – cool shivers of despair are added to the racked longing of "Six Days".

In Bristol, on the previous night of this UK tour, Radiohead's Thom Yorke turned up to duet on their Unkle collaboration. There's no Yorke tonight, but for the encore there's an impressive duel with a live drummer. A rampaging take on the new single, "You Can't Go Home Again", brings spontaneous outbreaks of air-punching appreciation from the crowd. He may take a while, but in the end Davis proves that his aural medicine is equally effective for the mind and the body.