Peaches, Cockpit, LeedsHot Chip, Astoria, London

In the flesh, Merrill Nisker is small and slender, but on a stage, as Peaches, she dominates like a colossus. The toughest female presence in rock 'n' roll today? No question. How about toughest of all time? Not that toughness is, per se, necessarily to be celebrated. But Peaches doesn't deal in the ultimately blank, vacant no-bull stance of, say, a Brody Dalle. What Peaches has achieved is no less than to reinvigorate the desiccated husk of feminism-in-rock, ditching its hollow stances, drenching it with X-chromosome juice and putting the sex back into sexual politics. Oh, and swearing like a sailor on shore-leave.

For most of her adult life, Nisker worked as a teacher (as wryly recognised with the title of her debut album, The Teaches Of Peaches), dabbling in muckabout bands on the Toronto circuit, until - as a member of The Shit (also featuring Chilly Gonzales) - she had a Damascene revelation, discovered her larger-than-life Peaches persona, and made her way to Berlin. Initially making her name on the early Noughties electroclash scene via the Kitty-Yo label, promoting her minimal electro-punk debut album as a one-woman show frontin' in front of a DAT tape, Peaches has steadily moved, via the more guitar-based Fatherfucker, towards the full-on "Rock Show" she promised on Teaches' sole rocked-up moment. She is now, essentially, a cock-rocker without a cock. (Well, apart from the giant inflatable one she throws out tonight...) Her confrontational crotch-thrusts and cold sexual demands could be intimidating to some, but the bisexual singer's aggressive objectification and commodification of the male as well as the female (exemplified by "Shake Your Dix" and "Two Guys For Every Girl") is actually welcome and liberating: it's a game everyone can play.

In 2006 Peaches is in control of the glam rock mothership, looping around planet pop in ever-erratic parabolae (previous captain: Marilyn Manson). A railway arch underneath Leeds station isn't the most glamorous place to touch down but, as with the Tardis, sometimes such things are ungovernable.

She steps out tonight in full sci-fi sex terrorist mode, starting off in a cape, stripping down to a purple glitter super heroine costume (complete with diamante lightning-strike strap on her Flying V guitar), and eventually bra and hotpants. Her all-female band, The Herms - short for hermaphrodites - comprise the androgynous JD Samsom of Le Tigre, Radio Sloan from Courtney Love's band, and the phenomenal, statuesque Samantha Maloney (who has drummed for everyone from Eagles Of Death Metal to Mötley Crüe). They wear silver foil jerkins with Flash Gordon shoulders, their faces painted with Thundercats whiskers. As a spectacle, the closest comparison is a female Iggy Pop backed by the Glitter Band.

The live show is a short but intense blast, including a routine nicked from James Brown in which she feigns collapse, is stretchered off by bandmates, before gesturing that she's OK and making a triumphant return. By the time she encores with her anthem "Fuck The Pain Away" ("Suckin' on my titties like you wanted me, calling me all the time like Blondie/Check out my Chrissie behind, it's fine all of the time..."), every fist is in the air. The adulation - the aspiration - is total. The boys wanna be her. The girls wanna be her. And why wouldn't they?

Last time I saw Hot Chip, two years ago in a small pub in Camden Town, they were five intense young men (looking like postgraduate chemistry students or sullen record shop employees) hunched over assorted consoles, led by the irascible, chippy, diminutive Alexis Taylor: one angry dwarf and four solemn faces (to paraphrase Ben Folds Five).

There's something touchingly comical about walking into their biggest show to date, in a large central London theatre, and seeing that almost nothing has changed. Their popularity has multiplied, partly thanks to their second album having been nominated for the Mercury prize (it was better than the winner, but then so were most of the nominees) but they haven't re-invested any of the proceeds into a flashy stage show: they've bought 15 coloured striplights and a cheap projector screen showing abstract textures.

But something indefinable has changed. Hot Chip are proof that in pop, redemption is possible. They are - please forgive the deliberately unfair caricatures - the glitchtronica nerds who saw the light and wrote killer tunes; the arch Hoxtonites who made an album that moves the soul as well as the feet.

Let's not exaggerate. Hot Chip were always a good thing. The difference is that Coming On Strong was in many ways a meta-pop album, a distanced commentary on what pop does, whereas The Warning simply does it. It's a shame that they've ditched from the live set "Down With Prince", their brilliant petty critique of fellow artists who claim kinship with the Purple One, but I can understand the reasons. They're in a different place now.

The refrain "Like a monkey with a miniature cymbal/The joy of repetition really is in you" from the brain-invadingly catchy "Over And Over" may seem snide, but I'm gonna give them the benefit of the doubt and presume that Hot Chip really do understand the joy of repetition. Even better is "Boy From School", which manages to be both plangent and poignant.

Showmen they ain't, and the set sags when they get into Spiritualized-style smack-gospel. Hot Chip don't bring the party. But you can't blame them for that. Peaches has just absconded with it, in her spaceship.

s.price@independent.co.uk