These psychedelic veterans' 35-year career is not for the fainthearted. However, the original psych-rockers are showing few signs of slowing down. Surprisingly sprightly founder member Dave Brock announces that the band stayed up all night "having a bit of a party". He then launches into a song that begins "Hashish! Hashish!" and is clearly untroubled that his lifelong trip "in search of space" may soon require a bus pass.

Even now, a gig by the outsiders' outsiders is like nothing else in the rock calendar. Their fans reek of ganja and arrive by silver machine (more likely to be Ford Fiestas than the glistening "hog" bikes of yore). The band's backdrop features little green men, their labcoats making them look like cackling scientists who ran off to join a cult.

However, nowadays Hawk wind use computers, address such topics as cloning and Martians, and their classic chugging sound - not totally unlike a washing machine spin cycle - has gained a subtle techno chassis.

This all attracts a new generation, who happily submit to the prospect of being parted from their minds. Most of the set is new, although the faithful are rewarded with pulverising renditions of sacred tracts like Brainstorm, which sounds like the Sex Pistols aboard a skyrocket. There's no Silver Machine or Urban Guerrilla, but these days lyrics about a "potential killer" who "makes bombs in the cellar" could land them in Belmarsh. It seems oddly normal to hear them wishing their fans: "Happy Christmas!" Then one of the band's older members hurriedly puts that right. "Happy Solstice!" he smiles.