Before hitting the road for a stadium tour later this year, Green Day decided to perform a gig in a slightly more intimate setting.

The legendary pop-punk trio was joined Tuesday by Jimmy Fallon in the subways of New York City to film a segment for "The Tonight Show" in which the band performed a surprise gig in front of bewildered commuters.

But Billie Joe Armstrong, Mike Dirnt and Tré Cool didn't show up sporting spiky hair while clad in leather clothes and signature black eyeliner. Instead, the band was initially disguised along with Fallon as run-of-the-mill subway buskers rocking out for spare change.

As the crowd began to swell – perhaps sensing something was afoot when they noticed beefed up security and plenty of cameras to boot – the performers ripped away their unkempt wigs and fake facial hair to reveal their true identities.

Green Day interview:Punk band to play full 2004 'American Idiot' album on tour

'Basket Case,' 'American Idiot' among Green Day subway set

The unplugged set included performances of the 1994 "Dookie" single "Basket Case," as well as "American Idiot" off the 2004 rock opera album of the same name.

As the band jammed in front of a crowd at the Rockefeller Center station in Midtown, many held their cell phones aloft to record the set and sang along with them, at times outmatching Armstrong and his microphone.

The raucous set also had "Tonight Show" host Fallon jamming alongside the band, tambourine in hand.

See footage of the performance here:

Subway performance will air on 'Tonight Show'

Green Day was in New York City for a small-stage SiriusXM show at Irving Plaza near Union Square to promote "Saviors," the band's upcoming 14th studio album.

Though "the Tonight Show" has not yet announced when the segment will air, the Rock & Roll Hall of Famers are gearing up for a tour later this summer alongside Smashing Pumpkins and other acts. The Saviors Tour begins May 30 in Europe before the U.S. leg kicks off July 29 in Washington, D.C.

The new music – the album drops Friday – isn't all the band will be celebrating during the upcoming tour. This year also marks the 30th anniversary of the release of Green Day's major-label debut, “Dookie,” and the 20th anniversary of the George W. Bush-era "American Idiot."

In an interview with USA TODAY, the band members said they plan to perform both albums in their entirety during the The Saviors Tour, as well as new material and plenty of fan-favorites.

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]