Hart formed Hüsker Dü in 1979 with Bob Mould and his friend Greg Norton. The band’s early material had them lumped in with the hardcore movement of the early 1980s. The band members received help from their parents in their early days. In Hart’s case, his mother let him use the copier machine at the credit union where she worked to make show flyers, and the band added $2,000 to an existing loan at the credit union to release the band’s first single, “Statues,” on their own label Reflex Records in 1981. Success existed on a small scale for the band; by 1982 Hart was unemployed and relied on support from friends and family.

In 1986, Hüsker Dü became one of the first key bands from the American indie scene to sign with a major label, inking a deal with Warner Bros. Records. However, tensions within the band worsened after signing with Warner Bros. Hart became addicted to heroin following the band’s tour behind their major label debut Candy Apple Grey in 1986; he was also (incorrectly) diagnosed as HIV-positive in the middle of that year. Mould and Hart were feuding openly about Hart’s drug use and creative conflicts, with Hart accusing Mould of ensuring he could not have more than 45 percent of the songs on each of the band’s albums.

The band dissolved after a show in Columbia, Missouri, in 1987. Hart was trying to quit heroin using a supply of methadone, but the bottle had leaked. Hart played the show, but Mould and Norton were concerned that Hart would soon be suffering from withdrawal and thus would be unable to play the next few shows. While Hart insisted he could perform, Mould had already canceled the dates. Hart quit the band four days later. Hart has said his drug use was not the reason for the band’s demise; rather, it was the tensions between the band members. Hart said, “It just became that it was easier to be around Bob if you were playing a part of Bob’s game,”and also said he felt Mould’s songs had become increasingly “square.”

Six months after Hüsker Dü’s breakup, Hart discovered that his diagnosis as being HIV-positive was incorrect. In 1988 he released the solo EP, 2541, on Hüsker Dü’s former label SST. The title is taken from the address of his former band’s office and rehearsal house, where the members had at one time lived. Marshall Crenshaw would later cover the title song, as would the Go-Betweens’ Robert Forster. After the release of the EP, Hart went further into sobriety, recording and releasing the album Intolerance and the associated EP All of My Senses in 1989 and 1990, respectively.

In late 1989, he formed a new band, Nova Mob, with Michael Crego on drums, Tom Merkl on bass, and Hart himself taking guitar duties. The band took their name from the novel Nova Express by William Burroughs; it had previously been used by an unrecorded group featuring the young Julian Cope and Pete Wylie. The band released their first EP Admiral of the Sea and album The Last Days of Pompeii in 1991. The lineup later changed with Marc Retish and then Steve Sutherland on drums, and Chris Hesler on lead guitar. The band routinely toured Europe to warm reception. Nova Mob released their second album Nova Mob in 1994, and disbanded after a supporting tour.

Hart returned to recording as a solo artist with the release of the live album Ecce Homo in 1995, and later released Good News for Modern Man in late 1999. On 21 October 2004, he and Mould reunited at the benefit concert for Karl Mueller (bassist for fellow Minneapolis stalwarts Soul Asylum), who was then fighting what would turn out to be a losing battle with cancer.

In tribute to Grant Hart and his work with Hüsker Dü, The Posies recorded a song entitled “Grant Hart” which was released on their 1996 album Amazing Disgrace.

Hart recorded his next solo album (and first in a decade), Hot Wax, in Montreal and Minneapolis. Hart told Britain’s Q in September 2006, “I’m working on some stuff with the Godspeed You! Black Emperor people. They’ve given more of themselves in a few weeks than Bob did in nine years with Hüsker Dü.” In 2008, Hart was one of the guest singers on Lotuk, the third album of Arsenal, a Belgian band combining roots and dance music. In the summer of 2008, Hart debuted a new track, “Schoolbuses Are For Children,” on his Myspace site. He released Hot Wax on October 6, 2009. Intolerance was reissued on February 9, 2010, on 180-gram vinyl, and The Last Days of Pompeii was reissued with extra tracks and new mastering on December 7, 2010.

In December 2012, Hart embarked on a short tour of Ireland with a new lineup, Colm O’ Herlihy on guitar, Dan Walsh on drums and Simon Dargan on bass In a Facebook Q&A, Hart commented: “I love playing with these guys. They let me make music rather than getting bogged down administrating a band’s business. They make it a joy with their self-starting ways” He confirmed this lineup for his upcoming European and USA dates. Most recently, Hart released the double album The Argument (based on John Milton’s Paradise Lost) in the summer of 2013.

In October 2013, documentary filmmaker Gorman Bechard released Every Everything: The Music, Life & Times of Grant Hart, a film about Hart which chronicles the musician’s life from birth to the recording of The Argument. Told in the style of the Errol Morris film The Fog of War, Hart is the only interview subject in the film.

Grant Hart married Brigid McGough Hart on July 5, 2017, at Church of the Assumption in St. Paul, Minnesota.

Hart died on September 13, 2017, at 9:02 p.m., at Fairview University of Minnesota Hospital, of complications from liver cancer and hepatitis C. He was 56 years old. He is survived by his wife Brigid McGough Hart and son Karl Turbenson.