The BMO Music Fest is a one-night urban music extravaganza that squeezes a lot of entertainment into a limited space of time. Seven major hip-hop and R&B artists will be on hand, all of whom could fill a club or even an auditorium on their own. This year's headliner is Shaggy, who remains the biggest crossover success in dancehall, a genre that was helped into the mainstream by his 1995 hit "Boombastic." He still has a place in the hearts of R&B fans due to his raw power as a performer and a tendency to pop up as a guest on other people's records.

Lil Jon, meanwhile, can still boast he's the "king of crunk," the slower, synth-driven hip-hop genre that is synonymous with the Dirty South, and which is only a little less dated than dancehall, even if it didn't make a dent on the pop charts until Lil John's 2003 hit "Get Low." But he's got nothing on Cuban-American MC Pitbull, who was absorbing the Miami bass sound in the mid-'90s when its stepchild crunk was still a distant dream of Lil Jon's.

Laid-back R&B crooner J. Holiday may be the most generic artist on the bill. He's certainly demonstrated less of a tendency toward electronic experimentation than sex-you-up vocalist Omarion. The vocal quartet T.O.K. incorporates enough dancehall to deflect the Boyz II Men comparisons that tend to fly their way, while chubby, adorable Sean Kingston mixes it all up — dancehall, rap, quiet storm — into a teen-friendly auto-tuned mix that's been scorching the R&B charts for two years now.