It was a grubby place in the no-glam San Fernando Valley, but Sound City recording studio was where some of the most popular and influential rock albums of all time were recorded. In its heyday, it was beloved by musicians and producers for friendly staff, a commitment to the essentials of rock 'n' roll, and its massive custom-built Neve analog sound board. Foo Fighter and film director Dave Grohl has assembled an entertaining history of the now-shuttered studio, interviewing staff and musicians. The often-debt-plagued studio survived each decade by luckily recording an era-defining blockbuster: Fleetwood Mac in 1975; Rick Springfield's Working Class Dog (1981); and Nirvana's Nevermind, in 1991. The film's first hour is a blast for music historians and tech-heads. But, the second half, in which Grohl jams with an assortment of musicians (including Steve Nicks, Springfield and a Historical Legend) at his studio (now home to Sound City's Neve board) is pretty dull.