Dave Grohl, best known as drummer for Nirvana and singer-guitarist for the Foo Fighters, knows what it's like to pack a bunch of musicians into a van and travel around playing gigs. He could have told us himself, certainly, but he decided -- apparently after reacquiring his old red van -- to get a host of other musicians to help him tell the tale.

The result is What Drives Us, a documentary about paying your dues as a musician before you can afford fancy jets and tour buses.

Grohl dipped into a varied mix of performers with stories to tell, including U2 guitarist The Edge, Red Hot Chili Peppers bassist Flea, AC/DC singer Brian Johnson, L7 bassist Jennifer Finch, Metallica drummer Lars Ulrich, singer-songwriter Ben Harper, Guns N' Roses guitarist Slash, Aerosmith singer Steven Tyler and Beatles drummer Ringo Starr. And many more.

Grohl also spends some time in front of the camera, sharing his own thoughts on his days in the van. As he explains:

All of the biggest bands in the world ... they had to start somewhere. Everybody I know started out like this -- in a van. You're crammed in there, all together for months, and it can be both disgusting and beautiful all at once. What happens in the van is the foundation of who you become. It creates this unique perspective that we all share.

I can empathize just a little, although my own experiences are more about driving a few hours at most with bandmates in a minivan -- or, more often than not, simply meeting the rest of the crew at the gig. Still, the stories are fascinating to hear!

Like Flea notes in one interview, he and his fellow musicians were striving "to live a life where you could just play music with your friends, in front of people and travel around and do it. It was like, here's your golden ticket to Oz ... your life is set. You've made it."

Along the way, you get to hear the reasons why these musicians were willing to pack themselves into tiny vans with people and gear to spend hours on the road. You'll learn about managing the space of the van, packing in all the equipment and still leaving space to eat and sleep, about the evolution of vans, accidents on the road, odd sleeping arrangements, dead piglets along the highway, losses, mutual support and pervasive flatulence. The film includes new interviews along with archival and personal footage from the road.

"I think it's great for the band in the van because you get to know each other," Ringo Starr explains in the film. "You know, you're locked in. You know, I think that was part of us coming together, as the song says."

It's fascinating for anyone who loves live music and has seen a touring band perform. There's more to it, you quickly realize, than simply showing up on stage with an instrument in your hand and a song in your heart.

Oh, and who would have imagined hearing Ringo say the Beatles, in their early days of touring, had to own up to their farts?