Orbital formed 10 years ago in Sevenoaks, Kent. One of the first identifiable bands in the nascent acid house scene, they took their name from the M25 motorway which circles London, and along which convoys of weekend hedonists would cruise in search of rumoured raves. But Orbital weren't content to stay on the merry-go-round of anonymous DJs and mysterious white labels. Acid house could be faceless and apolitical - a drug-fuelled shrug in the face of Conservative dominance - but the Hartnoll brothers went on Top of the Pops wearing No Poll Tax T-shirts. They would prove to be equally outspoken against 1994's Criminal Justice Bill, and made a practical pro-environment statement by recording the 1996 album track The Girl With the Sun in Her Head using solar power from a Greenpeace generator.

Their true significance, however, has been in showcasing the power of dance music in the live arena. Anyone who regarded techno as a cold, clinical music which could only be produced in the studio would have had their preconceptions blown away by the sonic waves emanating from Orbital's legendary 1994 Glastonbury set. That performance is regarded as a watershed in British pop culture; the moment when the barriers between the traditionally opposed genres of rock and dance were broken down as the crowd lost itself in a maelstrom of beats, a jetstream of synths and an aurora borealis of lights. In the midst of this barrage of sensation stood Orbital, resplendent in lab coats, shaved heads and welding goggles with lights fixed to the frames. They looked like freaky brain surgeons. In a way they were.

Orbital play Princes Street Gardens on August 13 at 8pm Even if you can't make it to the concert, you don't have to miss a second of Orbital's performance - thanks to Festival Revue. Broadcasting live coverage of the Edinburgh Festival on screens in Princes Street Gardens all through August, Festival Revue will also broadcast Orbital and support live from 8pm on August 13 on Channel 90 of Cable TV, and on the internet at www.festivalrevue.com. "Our technology means Orbital will be seen all over the world," says Paul Blyth, managing director of Festival Revue.