One afternoon last summer at Chicago’s Pitchfork Music Festival, a chunky, shambling young man wandered around in the backstage VIP area wearing a T-shirt and cut-off shorts that were oddly serrated, as if by a blind man. He had something illegible scrawled in Magic Marker on one leg. His hair sprouted in multiple directions. And his thick, wide-framed glasses appeared to have been borrowed from a CPA, circa 1971.

About an hour later, Dan Deacon took to the smallest of the festival’s three stages, the one mostly devoted to hip-hop and electronic acts, and quickly undermined his nondescript, record-store clerk appearance. His set, with low-tech loops and beats drawn from his album “Spiderman of the Rings” (Carpark), wasn’t a surprise to his fans, many of whom had been tracking his career on music Web logs for months. But it did catch the Chicago Fire Department off guard. At an outdoor event whose headliners included Sonic Youth, Cat Power, and Yoko Ono, Mr. Deacon stole the thunder. The crowd squeezing in to hear him swelled far beyond capacity, and an anxious fire marshal pulled the plug.

Like much about his adopted home of Baltimore, Mr. Deacon is happily subversive. During the past few years, while no one was looking, the city best known for spawning John Waters and “The Wire” has fostered a teeming underground scene, of which the composer and performer is a star. Several years ago, the former SUNY-Purchase student migrated with some classmates to a Baltimore warehouse. The group christened the space Wham City, and modeled the beehive of art and noise after Fort Thunder, a similar space in a former textile factory in the Olneyville district of Providence, R.I., that had been the hub of a late-’90s art collective.

Mr. Deacon, who performs Friday at the Whitney Museum, has a new endeavor. Along with the video artist and drummer Jimmy Joe Roche, he assembled the 40-minute video “Ultimate Reality,” which he has been screening at live performances (although, oddly, it will not be shown at the Whitney). The work is a giddy exercise in pop appropriation, with shades of Negativland irreverence, that nonetheless acts as a tribute to the life and work of Arnold Schwarzenegger.

The video is perfectly of a piece with Mr. Deacon’s music, which charms with a certain guileless enthusiasm. He’s got a knack for re-deploying pop culture memes, as he does on a piece inspired by “Wooody [sic] Woodpecker.” He takes the mocking, staccato laugh of the 1960s cartoon bird, begins to loop it, and manipulates its pitch to pay a kind of animated tribute to Steve Reich (whose 1965 minimalist masterpiece “It’s Gonna Rain” is the template for such beat science). But as the track unfolds, it’s the sweet, rudimentary melody of a tinkling xylophone that modestly compels the ears. The cartoon chuckles recur (sped-up and slowed-down voices of friends), swooping over giggly keyboard lines and catchy jingles that are irresistible in their deevolutionary zeal.

The same spirit abides in “Reality” (available as a Carpark DVD), which “samples” images from many of Governor Schwarzenegger’s films and transforms them into a kaleidoscopic freak-out. Mr. Roche rewires the narratives of such films as “Predator,” “Conan the Barbarian,” “Kindergarten Cop,” the various “Terminator” movies, “Total Recall,” and “Junior” to create a new story line that unreels as a mash-up of last action hero and awkward comedy star — with effects at once sublime and ridiculous.

Mr. Deacon performs Friday at 7 p.m. at the Whitney Museum of American Art (945 Madison Ave. at 75th Street, 212-570-3676).