One of the great guitarists of the classic rock era, Mike Campbell served as Tom Petty's lieutenant for the better part of their careers, sticking with him alone or with the Heartbreakers. Campbell occasionally worked apart from Petty -- notably, he gave Don Henley the music for his 1984 hit "The Boys of Summer" -- but he was there even when Petty went solo or when he reunited Mudcrutch, the country-rock group the pair played in prior to the Heartbreakers. The guitarist also launched a band called the Dirty Knobs during some downtime with the Heartbreakers around 2000, and after Petty's unexpected death in 2017, he made that band his primary concern, releasing their debut, Wreckless Abandon, in 2020. Campbell moved his name above the Dirty Knobs in the billing for their second album, External Combustion, but the group continued to play rock & roll in the vein of the latter-day Heartbreakers.

Born on February 1, 1950, in Panama City, Florida, Mike Campbell settled in Jacksonville, Florida by the time he was a teenager. When he was 16, his mother bought him an acoustic guitar and he bought his first electric not much later. Inspired equally by American folk-rock and the British Invasion, Campbell shared similar tastes to Tom Petty, who he met when his friend, drummer Randall Marsh, was auditioning to play in Petty's Mudcrutch. The band had just parted ways with their guitarist so Campbell was invited to audition as well, and he was hired on the spot.

Mudcrutch built up a following in Florida then headed to Los Angeles, where they landed a deal with Leon Russell's Shelter Records. "Depot Street" appeared to little attention in 1975, so Shelter dropped the band while retaining their option on Petty. The rocker soon put together the Heartbreakers with Mike Campbell and former Mudcrutch keyboardist Benmont Tench. Shelter released the eponymous debut from Tom Petty the Heartbreakers in late 1976 and it gradually found an audience with the single "Breakdown" cracking the Top 40 a year after its initial release. You're Gonna Get It! fared slightly better in 1978 but it was 1979's Damn the Torpedoes that made Tom Petty the Heartbreakers rock stars.

With Tom Petty the Heartbreakers dominating radio and MTV, Campbell seized session opportunities outside the group. Stevie Nicks cut his original "Stop Draggin' My Heart Around" in 1981 -- the Heartbreakers backed her on her recording, with Petty acting as her duet partner -- and the pair retained a creative partnership that stretched into the 2010s. The guitarist played on Jungle, the 1984 LP from fellow Shelter alumnus Dwight Twilley, which was overshadowed by his work on Don Henley's second solo album, Building the Perfect Beast. Offered to Petty, who rejected it as a possible tune for Southern Accents, "The Boys of Summer," a song Campbell composed while playing with a new LinnDrum machine, became a smash hit in late 1984, reaching five on the Billboard chart and snagging Henley the Grammy for Best Male Rock Vocal Performance.

Campbell and fellow Heartbreakers Benmont Tench and bassist Howie Epstein appeared on Bob Dylan's 1985 album Empire Burlesque, igniting a creative partnership that flourished in the following two years when the Heartbreakers served as Dylan's supporting band on a pair of tours. During this time, Campbell played on a bunch of records, ranging from Aretha Franklin's Who's Zoomin' Who? to the eponymous debut by Lone Justice, appearing on records by Peter Case, Brian Setzer, Matthew Sweet, and Randy Newman, as well as a pair of albums by Warren Zevon.

Campbell earned his first co-production credit on a Tom Petty record with 1985's Southern Accents. He kept this collaboration thriving even when Petty stepped away from the Heartbreakers for Full Moon Fever, a 1989 album produced by Campbell, Petty, and Jeff Lynne. This dynamic stayed in place throughout the '90s, a period where Petty released another solo album with 1994's Wildflowers, while the Heartbreakers backed Johnny Cash on a series of Rick Rubin-produced albums. With his Heartbreaker bandmates Benmont Tench and Ron Blair and former Mudcrutch drummer Randall Marsh, Campbell formed the Blue Stingrays, a surf rock busman's holiday who released the Surf-N-Burn album in 1997. A few years later, Campbell formed the Dirty Knobs, a garagey rock band rooted in the sound of '60s garage bands.

The Dirty Knobs were a way for Campbell to perform live when Petty was taking time off, which wasn't often. Petty continued with the Heartbreakers in the 2000s, keeping them active even when he reunited Mudcrutch for a 2008 tour and album. After two additional Heartbreakers albums, 2010's Mojo and 2014's Hypnotic Eye, Mudcrutch released 2 in 2016. It turned out to be the last album Petty released in his life. After wrapping up the Heartbreakers' 40th Anniversary Tour with a show at the Hollywood Bowl on September 25, 2017, Petty died of cardiac arrest on October 2, 2017.

In the wake of Petty's death, Stevie Nicks invited Mike Campbell to be one of two musicians to step into the vacancy left by Lindsey Buckingham in Fleetwood Mac (the other was Neil Finn of Crowded House). Campbell toured with Fleetwood Mac on their 50th Anniversary Tour in 2018, then he made the Dirty Knobs his first priority. Their debut LP was completed in 2019, and after releasing the track "Wreckless Abandon" in January 2020, they planned to issue the set the following March, followed by a concert tour. However, Campbell was briefly sidelined by a health problem that led to a hospital stay, and the release of the album was postponed. The COVID-19 pandemic soon led to the cancellation of their live dates, and the group virtually assembled to record a new song, "Lockdown II," that spoke with anger about the handling of the crisis; the track was issued in September 2020. The LP, Wreckless Abandon, was finally released in November of that year.

Working again with co-producer George Drakoulias, the Dirty Knobs knocked out a second album in the course of three weeks during the summer of 2021. The resulting External Combustion broadened the musical reach of the Dirty Knobs, incorporating a greater reliance on overdubs and '60s pop tricks, along with featuring cameos by Ian Hunter and Margo Price. When the record was released in March 2022, Mike Campbell moved his name above his band's on the credits, so External Combustion was officially credited to Mike Campbell the Dirty Knobs. ~ Stephen Thomas Erlewine, Rovi