"This is my first ever festival," beams Sam Sparro, raising a chuckle from the audience. So this suave Californian solo artist thinks this is a festival, does he? On consideration, though, he's right: this annual blow-out, which hosts 130 bands at 25 north London venues over two days, offers everything a festival does, including wretched weather. The critical difference is that you encounter the rain only while traipsing between venues. Perfect.
Unreservedly mainstream, Sparro is the odd one out in this mainly indie company, but his cool-breeze soul is a pleasant aperitif. If only Royworld were as toothsome. Some reckon they will be the next big 1970s-referencing thing, and they have the right sort of epic Mellotron drone. But they are tune-free, and stuck with the world's worst name to boot.
The queue for Toronto's Crystal Castles confirms their hotly tipped status. The boy/girl electro-duo produce an invigorating noise that makes the dancefloor a dangerous place to be. The Rapture did this kind of stuff five years ago, but they weren't lucky enough to have the yappy Alice Glass as singer, so watch this space. Stockholm's Lykke Li also attracts a crush; while there is not much to her apart from minimalist pop melodies and a baby voice, she has definitely got something.
Meanwhile, White Lies' show is so packed that the bouncers have stopped letting people in. What those outside are missing is a set by a group who only signed a record deal a month ago but already sound full-figured enough to step into U2's shoes.
Though the Crawl's primary function is to present tomorrow's music today, there are also some established names, including the Fratellis, the Wombats and Kano. This last has developed a Tim Westwood-esque mid-Atlantic accent, but he flies the flag for London's grime scene during a frenetic set. "I'm from London town!" he raps, and the words are sung back to him by 1,000 happy Crawlers.