Raymond Raposa, aka Castanets, is used to testing times. His latest album, In the Vines, documents a year of depression. While he was recording it, he was mugged outside his flat. Such experiences inform songs that are like travelogues, so at least this bizarre gig should give him some ideas. At the last minute, the San Diego man finds that the gig has been moved to a gay disco. He is here to play dark Americana. The dancefloor - padded walls, swirling lights and disco balls - looks like the one in the Alan Partridge scene where Steve Coogan's hapless radio host fantasises about dancing in a rubber thong. Still, Raposa suggests he is game for a challenge, following Willie Nelson's My Heroes Have Always Been Cowboys with a demand for requests. "Living On a Prayer!" shouts someone, ominously.

Raposa cuts an incongruous figure in a mechanic's cap, big beard and eyeliner, which gives him the look of a loner weirdo in an American film. "Drive me down to Reading, darling, we're gonna get some guns," he drawls over his guitar. Things get even stranger when he stands on one leg and yells: "Ow!" It is surely only a matter of time before he starts howling like a dog. However, his lyrics about ghosts, hookers, shadows and loneliness are darkly compulsive, and you wonder what he would sound like with his usual accompanying musicians, or in more sympathetic surroundings. As City of Refuge's whirring guitar loop is drowned out by chatter, he ventures on to the dancefloor to sing, his eyes rolling. Perhaps dark Americana has something in common with Saturday night Manchester after all.

· At the Windmill, London (020-8671 0700), tonight. Then touring.