Whatever else, Ozomatli certainly know how to end a show. Clambering off the stage to join the already seriously overcrowded audience, they somehow made their way through their wildly enthusiastic followers while chanting, banging drums and waving their instruments in the air, as they slowly headed for the counter at the back of the hall selling their T-shirts and CDs.

This band are something of a populist American phenomenon. They started out playing at parties and political benefits around Los Angeles, and evolved into one of the more entertaining global fusion exponents on the west coast. They began by mixing hip-hop with local Chicano styles, salsa and Mexican influences, and have now moved on to add almost anything else they can think of. In the process, they have developed a reputation for being guaranteed crowdpleasers, but perhaps it is time for another rethink.

This was the first night of La Linea, London's annual Latin festival, which was also opened by Ozomatli six years ago, when they gave a rousing performance at the Festival Hall. On that occasion, they looked and sounded like one of the freshest, most wildly original bands on the planet; but this time they were merely repeating a well-tested, reliably entertaining format.

The lineup included six singers and a three-piece brass section, and the aim from the start was to get the crowd swaying and clapping as they switched from Spanish-language hip-hop to salsa, before throwing in global influences. There was a burst of Arabic-style chanting on Believe, followed by a jovial burst of punk, a ska dance workout that looked like a Madness revival, and an excursion into reggae, with a treatment of The Tide Is High that owed more to Blondie than the Paragons. The range was impressive enough, and there were some strong songs from their back catalogue, including the acoustic ballad Cuando Canto, in which they strayed into Los Lobos territory, and the anthemic Saturday Night.

But for all the variety, it all sounded just a little too predictable. Ozomatli have settled down to become a safe, singalong party band. Earlier, there was more Spanish-language hip-hop fusion from Cultura Londres, a homegrown outfit whose set was enlivened by a display of some of the best capoeira dancing to be seen this side of Brazil. A solid start for this year's La Linea.

· La Linea festival continues at venues across London until April 30