Fifteen minutes after the show should have started, Cat Power’s non-appearance was starting to concern fans. The volatile singer – Chan Marshall to her mother – has a history of live disasters because of crippling shyness that drove her to drink. If she turned up at all, she might stop mid-song and burst into tears.

How strange, then, to see her skip onto the stage smiling, a cup of tea in one hand, lyric sheets in the other, and strike a comedy bodybuilder’s pose. Behind her were four male musicians – not the crack team of veteran Memphis soulmen who gave last year’s album, The Greatest, its rootsy blues backing, but a younger bunch with similar instructions.

When she emerged a decade ago with a band that included Sonic Youth’s Steve Shelley, Cat Power made noisy, unstructured, melodic rock. Since then, she has veered through quiet folk and Southern porch songs. For The Greatest, she filled out her sound, added a sweet, country edge to her melancholic vocals and finally gave up alcohol. Judging by lyrics littered with “I love you”, she had met someone special.

Cat Power, however, doesn’t do soft, at least not in a typical pop manner. Opening with a bluesy cover of Moby Grape’s Naked if I Want To, she performed with an intensity you could feel at the back of the Forum. Her voice escaped in a swell of emotion, not so much swooping above the piano as curling around it like thick, soulful smoke.

When she moved, she crept, clutching a hand-held mike to her chest. During her superb new song Willie, she walked with her legs poker-straight, like a little bird looking for feed. Half an hour in, when she finally spoke, it was to ask for the lights to be turned down on an already gloomy stage.

Tracks from The Greatest were hauntingly good, while covers culled from a previous album were turned into creepy torch songs, lethargic blues or, very occasionally, chirpy country-pop. The pace should have picked up more often and there were a couple of ill-advised choices, – although not the closer that melted from Gnarls Barkley’s Crazy into Patsy Cline's – but where Cat Power excelled was in sucking fans into her world.

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