Like many good ideas, the film “Sound City” started over barley and some hops.

Dave Grohl, former Nirvana drummer and now frontman of the Foo Fighters, had just purchased the custom Neve 8028 Console from Studio A of Sound City Studios, planning to install it at his private recording studio.

About two years ago, Grohl’s friend James Rota, of the band Fireball Ministry, helped Grohl move the massive board. The pair, both music geeks, rested and drank a few beers after the difficult transport. That’s when they began recalling all of the famous albums that had been recorded at Sound City Studios, which closed in 2011.

Grohl became more and more animated as they talked, Rota said. In honor of the 20th anniversary of Nirvana’s “Nevermind,” perhaps it would be fun to make a short film about the place where “Nevermind” — one of the most influential and important rock records ever — was recorded.

“He said, ‘Hey, you know how to make a movie,’ ” Rota recalled. It was true. To supplement his income, Rota was a production supervisor for films ranging from the “Chronicles of Narnia” franchise to the more recent movies “Parental Guidance” and “Chasing Mavericks.”

Over time, that small film grew and grew.

First-time director Grohl, now 43, calls the 106-minute documentary the most important thing he has ever done. “I wouldn’t be here if it wasn’t for that board,” Grohl said. “It’s a huge part of my life and history. It’s like being reunited with a family member.”

The film tells two stories tied with a common thread. The first story chronicles the story of Sound City Studios, the Van Nuys, Calif., recording studio that was the gestational partner for some of modern music’s most popular and critically acclaimed albums, ranging from Fleetwood Mac’s “Rumours” to Rage Against the Machine’s self-titled debut.

Opened in 1970, the old-fashioned analog studio closed in 2011 as high-tech, computer-assisted digital recording became the industry standard. “The studio has a Ripley’s Believe It or Not [story],” Grohl said. “People who casually listen to music never think about the room or the mixing console.”

The second story in the film focuses on Sound City’s analog console, which represents a dying ethic: people working with other people in a live setting, making music. It’s the antithesis to the contemporary music scene, where people make music in front of a computer. “Four people playing together — it’s hair-raising,” Grohl said.”That’s what makes magic.”

It’s the human element — not ProTools or digital recording — “that gives you the chills,” Grohl said.

Grohl contacted as many musicians as he could think of who shared his sentiment. Many legendary names ended up in the documentary: Trent Reznor, Mick Fleetwood, John Fogerty, Lindsey Buckingham, Tom Petty, Neil Young, Stevie Nicks, Foo Fighters’ Taylor Hawkins, Nirvana’s Pat Smear and Krist Novoselic, Metallica’s Lars Ulrich, Rage Against the Machine’s Tim Commerford and Brad Wilk, Queens of the Stone Age’s Joshua Homme and Alain Johannes, Ratt’s Stephen Pearcy and Warren DeMartini, Heaven and Hell’s Vinny Appice, Fear’s Lee Ving, The Pixies’ Frank Black, Black Rebel Motorcycle Club’s Robert Levon Been, Weezer’s Rivers Cuomo, Heartbreakers Mike Campbell and Benmont Tench, REO Speedwagon’s Kevin Cronin, Pat Benatar’s guitarist Neil Giraldo, Rick Springfield, Garbage man Butch Vig (producer of “Nevermind”), producer Rick Rubin and even Barry Manilow.