Roots lead a celebration of positive party hip-hop

The epic, high-energy sound of Philadelphia hip-hop crew the Roots has proved once and for all that, contrary to the history of rap’s chaotic stage shows, this band stands tall among the best live acts performing in any genre today.

Even their less than ideal spot at the end of Thursday’s four-hour Holiday Cooldown concert at the Universal Amphitheatre -- an evening crammed with other good acts playing miniature sets and lots of def poetry and irritating shout-outs in between -- couldn’t diminish the Roots’ impact, or the audience’s urgent, honest connection to this band’s great live sound.

This was the 10th annual Holiday Cooldown show for the Beat (100.3 FM), which more typically features the hottest R&B; and neo-soul acts to reflect the bulk of its programming, this year represented only by the suave, rooster-strutting hit machine Raphael Saadiq. He had the women on their feet with a medley of his hits, including two times through “Still Ray,” with New Orleans-style marching tuba taking the bass line.

But this year’s Cooldown was dominated by positive hip-hop, and the crowd was clearly ready to party with the heavier beats. Detroit’s Slum Village and L.A.’s Jurassic 5 set the tone with short, polished sets that showed off their tight ensemble vocal work.

Jurassic 5 DJs Cut Chemist and Nu-Mark stole the show with a pyrotechnic extended break that brought roars from the crowd when the latter created an impromptu beat composition from a child’s musical toy.

A set from New York’s legendary old school B-boys Gang Starr seemed erratic and somewhat dated by comparison, lacking the deft complexity and message of today’s monsters of hop. Guru and a guest MC did, however, stop their show in the middle to roundly curse the media for propagating “all this East Coast-West Coast rivalry.”

The fact that many of these acts have worked together extensively seemed to pull the show forward toward the band of live musicians that at one time or another has backed them all, the Roots.

Working at the height of their powers, the six-man Philly crew, anchored by drummer ?uestlove and fronted by MC Black Thought and joined by Frankie Knuckles on percussion and Rahzel as MC, pushed the manic energy of their seamless and highly musical assault to the level of the best rock show and then beyond, with the entire house dancing in the aisles.

Gifted rapper Common was the guest MC on the first three songs, leading the band along a clean, easy through-line of rhythm and power, especially on his hit “Light.” He re-emerged later with some impromptu break-dancing. Talib Kweli guested, as did eccentric neo-funk man Cody Chesnutt, wearing a long quilted skirt and purple pimp hat and jamming on a hollow-body electric.

A towering version of “Break You Off” ended with MC’s Scratch and Rahzel spitting out some outrageously complex beat-boxing, including a brilliant, all-vocal dramatization of the light-saber battle between Luke Skywalker and Darth Vader (“I will never join the dark side!”) and a booming rendition of “Planet Rock.”