He is best known by his alter ego Har Mar Superstar, a character whose sweaty, energetic live performances were once infamous for often concluding with a perspiring, de-layered Tillmann disrobed down to a pair of briefs.

"[8] In 2000, he enlisted the help of several Saint Paul musician friends and the result was the pseudonymously self-titled album "Har Mar Superstar" that appeared on Kill Rock Stars in 2001.

[9][10] After his follow-up album, You Can Feel Me, elevated Har Mar's popularity in the U.S. and put him on the map in the United Kingdom, his stage outfits became more theatrical and several live shows featured female dancers.

By the time the third album, The Handler, was released in 2004, Har Mar Superstar regularly toured with a drummer and a bassist to fortify the prerecorded material.

Fabrizio Moretti and Tony Bevilacqua have served as Har Mar's rhythm section, playing drums and bass guitar respectively.

Har Mar sings and plays percussion during live shows and is featured on the recorded version and video of "Trick for Treat", a song on the band's debut album, Stainless Style, which was nominated for the Mercury Prize in 2008.

Playing cities throughout the U.S., Canada, and the U.K. in 2009 and 2010, Har Mar's Dark Touches touring band featured Denver Dalley on guitar, Jeff Quinn on bass, and Will Rockwell-Scott on drums.

In February 2011, Har Mar started recording and performing with the soft rock-inspired band Gayngs and experimental rock group Marijuana Deathsquads.

Har Mar and Marijuana Deathsquads teamed up for monthlong residencies in Los Angeles at Spaceland, in New York City at Bowery Electric, and in Austin, Texas.

The band is Nelson Devereaux, Jake Baldwin, Adam Hurlburt, Ethan Elseth, Aaron Baum, and Ryan Mach, and everyone had a hand in co-writing.

Har Mar has been spokesman for Vladivar Vodka,[16] which produced a series of TV commercials that gained an underground cult appreciation for their blatantly sexual content.

[18] He also contributed a cover of The Association's "Never My Love" to the film's soundtrack, with additional vocals by Adam Green, instrumentation & production by Flowers of Doom (Josiah Steinbrick & Matthew "Cornbread" Compton), and Flea on trumpet.

[19] On October 26, 2009, Har Mar Superstar was the musical guest on Late Night with Jimmy Fallon and earned rave reviews for his performance of "Tall Boy", immediately increasing his popularity in North America.

[18] In October 2014, Har Mar returned to Never Mind the Buzzcocks alongside Nicole Scherzinger, Kerry Godliman, and James Acaster.

Har Mar performs the theme song, and is the lead character of the "Skeleton Crew" band, for the 2017 Netflix revival of Mystery Science Theater 3000.

[24] Tillmann was honored with a star on First Avenue's outside mural,[25] which recognizes performers who have played sold-out shows or otherwise demonstrated a major contribution to the culture at the venue.

"[27] After anonymous sexual misconduct accusations against Tillmann emerged, First Avenue buckled to an organized series of complaints, and Har Mar Superstar's star was painted over.

"[37][38][39] The Star Tribune published a fourth anonymous accuser's narrative in a follow-up article, and reported a brewery severing business ties.