That’s the Melvins covering the Butthole Surfers’ Graveyard in front of our Street Treats Truck in Chicago. No one here at Jeni’s ever thought we’d type that sentence, but we’re geeked that the time has come.

Here’s how it went down:

The set-up: While we were in town last month to scoop at the Pitchfork Music Fest, we’d made a secret date with the Melvins via the A.V. ClubThe Onion‘s excellent non-satirical arts and culture arm. The A.V. Club’s “Undercover: Summer Break” sets up bands in secret spots throughout Chicago, rolls tape, and makes magic. So when they extended the invitation to us to participate we pounced. Anything The Onion/A.V. Club is for, we’re for.

The musicians and the song: The Melvins and the Butthole Surfers have been plying their trades for 30-odd years. Readers of a certain age (and taste in music) know Seattle’s Melvins as one of Black Sabbath’s direct descendants—and as one of the prime influences of Kurt Cobain. No Melvins, no Nirvana. And Austin, Texas’ psyche-rock/psychotic-rock Butthole Surfers, Generation X will recall, were a MTV mainstay thanks to their mid-’90s tune Pepper. (For the record, careful readers, that’s Surfers’ ex-bassist Jeff Pinkus (on mirror Flying V!) alongside the Melvins playing in the video above.)

The kids: If you haven’t already discerned, children aren’t exactly the Melvins’ typical audience. It took a while before Twittering music freaks figured out that the Melvins were playing for free in Humboldt Park. What great fortune for the kids. They just happened to be there playing in park when Melvins main man Buzz Osborne announced “Free ice cream!” and they had unimpeded access to the truck. Fantastic. Does anything more swiftly move kids to action than those three words?

Ice cream, a perfect summer day in Chicago, and raw, amplified power. Cheers to the Melvins, The Onion/A.V. Club, and all of our new friends in Chicago. And P.S.—More details about our first-ever scoop shop in Chicago will be announced soon. Stay tuned.