‘The show must go on’ is easier said than done

One of the most surprisingly tense experiences at the movies so far this year is “Rock the Bells,” a documentary about a promoter’s attempt to reunite rap superstars the Wu-Tang Clan for a July 2004 San Bernardino festival.

Chang Weisberg hustles to put the daylong event together despite the usual stumbling blocks -- local authorities, promotion, technical difficulties, etc. -- planning carefully but also setting some traps for himself. He oversells the venue and skimps on security. His biggest obstacle, however, is his star act.

The Wu-Tang Clan has long been simultaneously omnipresent and elusive in hip-hop. The beloved collective of nine (or 10) rappers has won awards, sold millions of records and flooded the market with solo efforts, but it has been notoriously difficult to assemble for concerts. That the Clan, made up of so many artists with solo careers -- including the infamously unreliable and bizarre Ol’ Dirty Bastard -- would be completely reunited onstage for the first time in years causes a frenzy. Despite a talented and diverse lineup of artists at the festival (particularly impressive are MC Supernatural, Eyedea + Abilities, and provocateur Sage Francis), it’s the reclusive “ODB” -- or rather, his absence -- that drives the story.

Filmmakers Casey Suchan and Denis Henry Hennelly provoke conniption fits. They capture the escalating tension as crowds threaten to overwhelm staff and ODB’s idiosyncrasies threaten to torpedo the reunion. We learn enough about Weisberg’s background (he refinanced his house for the festival) and see enough of his cohorts’ scramblings to become involved. As the temperature climbs over 100 degrees at the outdoor venue and thousands of fans crush forward, can Weisberg and Wu-Tang leader RZA avert disaster by persuading ODB (who died later that year) to come out of his tailspin?

“Rock the Bells” is stressful to watch, but its entertaining stage performances and document of people under pressure should interest even non-rap fans.

“Rock the Bells.” MPAA rating: Unrated. Running time: 1 hour, 42 minutes. Exclusively at Laemmle’s Grande, 345 S. Figueroa St., downtown L.A., (213) 617-0268.