Stereolab Shepherd's Bush Empire, London
Stereolab are such a regular presence on the festival circuit that it's odd to see them without the mud squelching around your feet and some berk in a jester's hat blocking your view. If you've only caught them at such gatherings, you'll be accustomed to them as a Saturday tea-time fixture who make pleasant, pulsing, melodic pop songs that straddle the line between easy listening and defiant experimentation. In short, the sort of band who will never be caught shouting "Hello Glastonbury, are you ready to rock?"

Indoors, and in the dark, they feel and sound like a different band. Tougher, nastier, and more driven. The set they played at Shepherd's Bush Empire on Saturday was predictably biased in favour of their latest album Dots and Loops, their ninth and most diverse collection yet (if you're looking for proof, skip to "Reflections in the Plastic Pulse", a 17-minute flotation tank epic that takes in wine-bar jazz, Kraftwerk ambience and a few Casio keyboard doodles). As such, you didn't feel passive in the experience: as the different musical styles jostled together they created a sense of unease that made your body work hard for the privilege of dancing.

One of the band's two female vocalists, Laetitia Sedier, maintains that their last singles, the Bacharach-esque "Miss Modular", deserved to be a hit because "there's nothing weird about that song". Perhaps not, but its idiosyncrasies are brought sharply into focus when it's thrashed out live alongside older songs like "Tomorrow is Already Here", which is the aural equivalent of waves lapping at your feet, or the mean, throbbing "Metronomic Underground", both from the Emperor Tomato Ketchup album.

Of course, if you're looking for synchronised dancing and inflatable nudes, you're in the wrong place. Listening to Stereolab play can be a life-affirming, mind-boggling, even religious experience, more euphoric than that bit at the end of a Johnny Mathis concert, where he does "When a Child is Born". Watching them is closer to observing two hours in the life of a sixth-form study group, all sensible cardigans and scholarly concentration. But remember what your mother always told you. Never judge an Anglo-French avant-garde Marxist pop band by its stage manner. Anyone capable of making music that can justifiably claim to provide the missing link between Astrud Gilberto and u-Zig is entitled to grace the nation's stages dressed in leopard print and taffeta if the mood takes them.