Once the Proms are back, a whole audience comes out of nowhere. Nobody used to know what it did for the rest of the year, until the BBC discovered in the Eighties that a large chunk of it went to English National Opera (I wonder if it still does). But what about the audience that doesn't go to the Proms? After all, there's rather a lot of music that they leave out - everything but the extended version of the classical repertoire that migrates to the Royal Albert Hall for the season. These days, you'll find those lost souls being sought out by just the places that don't pick up the Prommers, the other main concert halls of the City.

Evidence: tomorrow night on the South Bank, a choice between traditional music from Vietnam and the latest instalment of the JVC Capital Radio Jazz Parade. Meanwhile at the Barbican, the Kronos Quartet (right) interrupts its four-day festival of new music (quite tough stuff this time) to present the Algerian musician, Cheb Mami. By the weekend, the smaller halls back at the South Bank are getting into the swing of things with the start of an 'American South' week. The south of the States, that is. Blues and gospel and a Texas Night build up the pace to a grand finale on Saturday 30 July with the Savoy Doucet Cajun Band. Authentic barbecues are promised too.

On into August, and within a few days you can catch musicians from Uruguay and Brazil, with dance and music theatre on the way. It all adds up to the kind of mix that London's concert life could include all the time, if only. . . Well, they say they are working on that, and that within a year diversity will rule every week. Meanwhile, when you're tired of queuing for two hours to stand and listen for another two, here's a chance to expand your horizons just a few stops down the Circle Line.

Barbican Hall (071-638 8891)

Royal Festival Hall (071-928-8000)

(Photograph omitted)