When Dave Grohl air-drums, you can still hear a sound. This isn’t the answer to the old tree/forest riddle, nor confirmation of the more recent in-space-nobody-can-hear-you-scream hypothetical, just a fact: The Foo Fighters frontman goes at the task of keeping imaginary time just like he does everything else, with full-throttle energy, and so his forceful rhythmic chopping has the insistent, metronomic whirring of fan blades. That is, as long as he’s not air-drumming along to something loud.

“I know what time it is,” Grohl says excitedly, ejecting the Butthole Surfers from his Chevrolet minivan’s car stereo and popping in a new selection. It’s a balmy spring day at the end of March, and we’re inching our way through a typical Los Angeles rush hour on the way to a Foo photo shoot. In the passenger seat beside Grohl is the most recent addition to the new Foo revue, drummer Taylor Hawkins, who joined the band all of three weeks ago; bassist Nate Mendel slouches in the backseat next to me. “This is one of the five greatest songs ever,” announces Grohl, and the speakers swell with the unholy strains of “Mob Rules,” Black Sabbath circa 1981—at least a couple years after the sun had creatively set on Sabbath. Grohl jacks the volume up a couple of decibels as Ronnie James Dio lets out a growth-stunting shriek. “That’s totally Chris Cornell!” insists Grol of the banshee wail, before starting to swat along joyfully as the drum onslaught kicks in.

For Grohl, air-drumming to “Mob Rules” is no mere miming of wrists and hands. No, even though he’s spent most of the last two years more or less exiled from his drum kit as the Foos’ guitarist and singer, he still has every percussive moment memorized, his invisible sticks striking unseen drums just above the steering wheel, clanging a high hat somewhere near the rearview mirror, and thumping the kick drum next to the brake pedal, interrupting the groove only to reengage with the act of driving. As Hawkins begins hammering away the ether alongside his bandmate, I’m suddenly transported back the scene in Wayne’s World where Wayne, Garth, and their bandmates rock out while rolling to “Bohemian Rhapsody” by Queen, which happens the be the all-time favorite band of Foo Fighters guitarist Pat Smear—at this moment riding behind us in his girlfriend’s car—a man who, it should be noted, moves to the time of a completely different BPM altogether.

“If this record came out today, it’d be huge!” gushes Grohl. “Well except for the fact that the rest of the album sucks, but this song would be huge!” “Yeah,” responds Hawkins over the din, “especially if it was produced by Steve Albini and it had the guitar solos cut out and three of the guys in the band had short hair!” Hawkins starts crooning along with Dio, performing his best Bic-lighter-flicking, main-floor falsetto. “Dio,” laughs Grohl, turning to the backseat. “He’s the fucking coolest little midget in rock.”

Yes, Dave Grohl is having fun again. Although the effusive, gregarious Grohl seems to perpetually have a smile on his face—he looks more like he’s in a state of nirvana than like a former member of that band—it goes without saying that things haven’t always been that chipper for him. It’s been three years since the infamous tumult of Nirvana’s chaotic final days, just a few months since the dissolution of Grohl’s marriage, and a mere weeks since the departure of drummer Williams Goldsmith following the somewhat-less-than-seamless recording of the Foos’ second album, The Colour and the Shape. That Grohl has managed to pull through each hardship—”nothing should ever just come to a screeching halt,” he philosophizes with his sunny disposition intact due in large part to the irrepressible Smear, a founding member of late-’70s punk pioneers the Germs who played alongside Grohl on Nirvana’s final tours. “Working with Pat is non-stop entertainment,” alludes Grohl. “I’ll be onstage and feeling insecure, like I’m ripping people off because I’m a drummer, not a singer and a guitar player, and I turn around and see Pat and he’s got white pumps, black leather pants, white feather boa, white guitar, and I’m just like, “Yes! I’m back into it now!”

A similar sense of exuberance pervades the Foos’ musical offerings. Grohl’s delicate vocals glide over thick, crunchy guitars without the weight sonically and subtextually—that has become associated with the “N word” and the “G things.” Tracks like “My Poor Brain,” “Up in Arms,” and “Enough Space” still employ the quiet-verse/loud-chorus dynamic that Nirvana helped craft into gold sounds and platinum breaks-on “New Way Home,” Grohl’s voice leaps quite literally from a whisper to a scream-but Grohl’s songwriting relies less on Prozac than adrenaline; Foo tunes are more hummers than bummers.

“This band is relatively free of drama; it’s just a totally different scenario,” says Grohl. “Nirvana was nuts, it was crazy. I made my way through all of that other bullshit, and now I’m back to square one. That feels nice.”

Is it simply his status as bandleader, I ask Grohl, that makes the difference in his demeanor? “I think it’s the subtraction of drama,” he replies. “The Foo Fighters are a bunch of boring people, we really are. With Nirvana there was always something up someone’s sleeve.”

He pauses for a moment, playing back his last comment in his head, then starts to laugh.

“That was horrible,” he chuckles incredulously, shaking his head. “I can’t believe I just said that.”