Steven McDonald began his career in 1978, when he and his brother Jeff were 11 and 14 respectively. During those times, they lived in Hawthorne, California and were discovering underground music through Creem and Rock Scene magazines. Their real inspiration for the punk rock music began with Black Flag. Despite their age, The Flag added them to their member list. Soon after, they formed a band Redd Kross and performed their first show titled “Red Cross” at the eighth-grade graduation of one of their classmates.

McDonald produced an album by The Format, Dog Problems, on which he played bass and sang backup vocals on a few tracks. He later produced, engineered, and mixed fun.’s debut album, Aim and Ignite, as well as performing as a bassist and backup vocalist on some of the songs. He was also one of the various band members on the original Tenacious D album, along with Dave Grohl; keyboardist Page McConnell of Phish; guitarist Warren Fitzgerald with band frontmen Jack Black and Kyle Gass. He appeared with Tenacious D on MADtv playing “Lee” and “Tribute”. McDonald also featured briefly on bass in Kyle Gass’ side-project Trainwreck in 2002 and 2003, under the pseudonym “Slim Watkins”, before being succeeded by John Spiker.

In 2015, it was announced that McDonald would be joining the Melvins. He recorded four songs with the band, which were first released on the limited edition EP War Pussy and later included on the album Basses Loaded. Their first full release with McDonald, a double album titled A Walk with Love & Death, was released on July 7, 2017.