As the house lights went down, the laser beams went up and The Who emerged on stage, it looked like a scene out of Close Encounters Of The Third Kind: Planet Who had arrived.
They may be getting older in body but Roger Daltrey and Pete Townshend clearly feel younger than ever. Their massive sound, fuelled by those Who power chords, thundered over the applause while Zak Starkey's drumming was like a one-man firework display.
Having just completed a new album, Wire And Glass (the first new Who material in 25 years), with a request (from Townshend) to play at Glastonbury 2007 pending, they seemed to be revelling in renewed vigour as well as the rapturous welcome they received from Brighton.
Immediately firing into Who Are You, Townshend seemed relaxed in trademark shades but Daltrey was somewhat confused, laughing midway though the first song and singing "I don't f****** know, who are you? Who am I?" and saying at the end he had left part of his brain in Leeds the night before.
There was a sense of nervous anticipation as new tracks were presented. The crowd listened politely and although Townshend joked: "You'll get used to it," he and Daltrey seemed happy with the response.
They rewarded their audience with a succession of old favourites played with maximum energy and volume.
Without bassist John Entwistle it is a different show but Townshend dared to fill the hole by whirling his arms around and bashing the side of his guitar with his fist even more triumphantly than usual.
Daltrey did his customary trick of wrapping himself up with his mic lead and swinging it around his head like a lasso. His voice was strong but with his short hair and specs, jeans and a shirt, as opposed to the bare chest, flowing locks and kaftan of his youth, this showmanship didn't quite scale the heights of yesteryear and at times he looked tired.
Yet they are still great. After tracks from Tommy, a beautiful, gut-pummelling acoustic version of Drowned from Quadrophenia, a few fluffed lyrics and a lot of sweat and pounding, the band crashed to the end of their two-hour set.
Yes, they have played better gigs. Yes, they are getting on a bit and yes, half the band are dead, but with songs this good and energy this tremendous, Who cares!