Dave Grohl’s documentary “Sound City,” which debuted at the Sundance Film Festival in January, is superior to the soundtrack. The Foo Fighter frontman recruited friends and star musicians featured in his film to create new music captured on his beloved custom-built Neve 8028 console — which is the true star of his film. Grohl’s Foo bandmates Taylor Hawkins and Pat Smear, Nirvana’s Krist Novoselic, Josh Homme, Trent Reznor, Rick Springfield, Lee Ving and Stevie Nicks all perform. And Paul McCartney appears with the surviving members of Nirvana on the rocker “Cut Me Some Slack,” which sound more like Wings than Nirvana. There is relentless energy captured on this soundtrack, especially on Ving’s “Your Wife is Calling” and Springfield’s “The Man That Never Was.” But the end result is less than the sum of its parts, with some disappointing overdubs, most notably on Nicks’ track, which contradicts the message of the film — people making music together, live. The soundtrack, called "Sound City: From Real to Reel," often sounds like a collection of out-takes best left on the cutting-room floor.