POP MUSIC REVIEW : The Roots Deliver Dazzling Mix of Rap, Complex Rhythm

Beware of the Roots, the new Philadelphia rap group that performed Wednesday at the House of Blues. This foursome may spoil you for live rap. Once you see them in action, other acts will seem fairly feeble.

The rapper known as Black Thought may be the most mesmerizing performer in the genre, a whirlwind with a machine-gun delivery and the kind of infectious intensity that sucks you into his world. Even when you couldn’t tell what he was saying, you were still caught up in the flow and rhythm of his performance.

This East Coast style relies on dazzlingly complex rhyming rooted in jazz. Unlike most rap groups, the Roots don’t use taped accompaniment. The other three members are skilled jazz/R&B; musicians who lay a solid foundation for Black Thought’s frenzied rhyming.

What may hamper the group’s progress is that it doesn’t seem quite gritty enough to reach the primary rap audience--young black males. So far its audience has been mainly the college, alternative-rock crowd. Rappers without a strong black following often flame out quickly.

The opening act was the Watts Prophets, a group that was rapping before it was called rap. Prominent in the ‘60s and ‘70s, they recited angry poetry accompanied by jazz, speaking out against racism while promoting black self-esteem.

These three veterans are still doing the same thing, but in a climate that’s been changed by the rage and violence of modern-day rap. What once seemed cutting-edge and daring now seems tame and old-fashioned--packing about as much wallop as the intellectual, coffee-house radicalism of the ‘50s and ‘60s.