The afternoon is dreich — a Scots word for the peculiarly gray Scottish weather — but Stuart Murdoch and Stevie Jackson don't mind. The leaders of Belle and Sebastian, one of Glasgow's hottest indie-pop bands, are busking on the Great Western Road, the main artery through the city's leafy West End. Murdoch is strumming the chords to Blue Moon of Kentucky on a 12-string guitar while Jackson picks out the tune on his banjo. A middle-aged woman — busy shopping and oblivious to their pop star status — tosses some coins into the open banjo case. Those who do recognize the lead singer and guitarist nudge their friends, offer a shy smile, and hurry by.

Busking in the street is something Murdoch and Jackson do for fun: only four days before, Belle and Sebastian were playing to over 30,000 at the Benicassim Festival on the east coast of Spain. "The nice thing about coming back to Glasgow," says Murdoch, is that "... nobody gives a f__k what you look like or who you are." That, he says, is "a great thing for living and songwriting."

If you're wondering how a major pop act can pass unmolested in Glasgow's streets, it's because the city has an embarrassment of rock riches — think Detroit and Liverpool in the mid-1960s, Seattle in the early 1990s. Scotland's biggest city (pop. 600,000), 570 km from London's media maw, has always been an underground music incubator, and some of its bands (Simple Minds, Wet Wet Wet, Travis) have had chart-toppers over the years. But now Glasgow is churning out talent by the busload. At Benicassim, there were so many Glaswegians on show that Murdoch and Jackson might have wondered if they'd left home at all: Primal Scream, Teenage Fanclub, Snow Patrol and Franz Ferdinand — one of the hottest bands on the planet, having sold over 1.5 million copies of their debut album. Along with Belle and Sebastian and Snow Patrol, they have been nominated for Britain's prestigious Mercury Music Prize (Primal Scream won the first prize way back in 1992).

How did Glasgow suddenly get so prolific? It wasn't sudden at all. The city's underground scene has been thriving for years, with a legacy drawn from the postpunk Orange Juice and their label Postcard Records, the swirling feedback of the Jesus and Mary Chain, and the Chemikal Underground label set up by indie champions the Delgados in the mid-'90s. "There has always been a brilliant music scene in Scotland, especially Glasgow," says BBC Radio Scotland presenter Vic Galloway. "But it's currently being noticed by London and the mainstream. It hasn't been for a long time."

The mainstream began to pay attention thanks to the spectacular success of Franz Ferdinand, who came together at the Glasgow School of Art. They put on performances — part art show, part concert — in an abandoned warehouse called the "chateau," and gradually honed their riff-driven pop. Singer and guitarist Alex Kapranos believes that couldn't have happened in just any city. "If you started doing something like the chateau in [London]," he says, "the [media] would be there, there would be 50 A. and R. men, and you'd have a genuine underground and vibrant scene completely crushed at birth."

As well as inspiring homegrown talent, Glasgow's underground scene draws acts from further afield. Originally from Fife, Dogs Die in Hot Cars moved to Glasgow in 2000 after a fallow year in Edinburgh. They have since signed to V2 and are now bathing in praise for their debut album Please Describe Yourself. Snow Patrol are originally from Northern Ireland. It took them longer to gain mainstream success, but their double platinum-selling third album, Final Straw, was last week still Top 5 on the U.K. album chart.

The music industry, never shy to milk a good thing, is now watching Glasgow closely for new bands to sign. On a Monday night in August, London independent label Fierce Panda is staging a showcase gig of local bands featured on a CD called Glowing Underground. The location is auspicious: King Tut's Wah Wah Hut, where Oasis were first sighted by impresario Alan McGee in 1993. Simon Williams, boss of Fierce Panda, says the show is meant to give new talent a chance. "If you're a new band and you want to come and play London it's a nightmare exercise," he says. "It's incredibly expensive, and that's if you don't crash your van, get your mobile phone nicked, and you actually get paid a bit of money."

The bands at King Tut's seem grateful for the opportunity. After an impressive set of sharp indie tunes from Odeon Beat Club, a band called Multiplies serves up a tight range of prog and pop that has even keyboardist Graeme Ronald's parents dancing. Afterward, Ronald and drummer James Hamilton muse about the North-South divide in British music. "People down in London," sniffs Ronald, "aren't really impressed when they hear, 'Oh this band are really big in Glasgow.'" Hamilton adds: "But then again, London bands suck." That kind of attitude will keep Glasgow rocking long after the current wave of A. and R. men has moved on to the next hot town.