Since all but the biggest of classic soul music's living stars have fallen into various levels of obscurity, virtually any attempt to document the genre's history counts as a public service. On those grounds, D.A. Pennebaker and Chris Hegedus' Only The Strong Survive has to count as a success, though an otherwise unsatisfying one. Filmed between 1999 and 2001, the film catches up with ex-Supreme Mary Wilson, the Chi-Lites, Sam Moore, Wilson Pickett, Jerry Butler, and others, all of whom acknowledge the good fortune of simply staying alive in a business that, by one means or another, has claimed the lives of so many. Among them, Moore tells the most harrowing tales: A New York limo ride allows him to revisit the streets where, after the breakup of Sam & Dave, he spent a decade selling cocaine and heroin to support his own addiction. It's frequently frustrating how often the film cuts away from such stories just as they get interesting. Much of the blame can be placed with supercilious producer and host Roger Friedman, a tireless enthusiast for whom questions would only interrupt the constant gush of praise. He's like Inside The Actor's Studio host James Lipton reborn as a High Fidelity geek, and he continually clashes with the Pennebaker/Hegedus fly-on-the-wall approach. (In his other job, as a Foxnews.com celebrity columnist, Friedman heaps the same high praise on Cher's greatest-hits album and Liv Tyler's recent wedding, which suggests that his good taste only stretches so far.) Factor Friedman out, however, and plenty of highlights remain, both offstage and on, including priceless footage of Carla Thomas and her late father Rufus Thomas, the cornerstone of post-war Memphis music who recorded for Sun and Stax before becoming a beloved radio personality. Though it's dispiriting to see the Chi-Lites attempt to drum up enthusiasm for "Have You Seen Her?" before a sleepy crowd, much of the performance footage is electrifying, and nearly all of the interview subjects are compelling enough to warrant longer segments than Strong's scattershot approach allows. With last year's Standing In The Shadows Of Motown, Pennebaker and Hegedus' film could mark the beginning of a welcome trend. But while Only The Strong Survive is essential viewing for soul fans, as a documentary it never makes the needed connections among the artists, their music, and the lives they lead.