As the co-songwriter of Hüsker Dü, Hart's songs (such as "The Girl Who Lives on Heaven Hill" and "Turn on the News") received praise from critics and contemporaries. His vocal style, in contrast to that of Hüsker Dü bandmate Bob Mould, had a more measured and melodic delivery. His choice of lyrical themes, which ranged from teenage alienation in "Standing by the Sea" and the depiction of a murder in "Diane," to playful story-telling in "Books About UFOs," helped to expand the subject matter of hardcore punk.