Blues-rock guitarist Gary Moore, who had a successful solo career and worked with countless musicians, but is perhaps best known for his stint with Thin Lizzy, has died of unknown causes. He was 58.

Moore joined the Dublin-based rock band Skid Row in 1969, when he was only 16. It was there that he met Thin Lizzy founding member Phil Lynott, who brought Moore in to replace departing guitarist Eric Bell in 1973. The band recorded three songs with Moore on 1974’s Nightlife album, with Moore contributing a standout solo on the single “Still In Love With You.” By that point, Moore had already released his first solo album (1973’s Grinding Stone), and left Thin Lizzy after just four months to continue focusing on his own career, but he would return to the group in 1978 to work on Black Rose: A Rock Legend. Moore walked out again during a subsequent 1979 tour, but came back a final time for the group’s 1983 farewell tour, and can be heard on the double-live album Life.

Though he'd left the group several times (and often without warning), Moore remained on amiable terms with the members of Thin Lizzy, and forged a successful solo career co-writing songs with Lynott, scoring Top 10 hits like “Parisienne Walkways” and “Out In The Fields” (one of Lynott’s last recorded songs before his death). He also briefly formed the hard-rock group G-Force to tour with Van Halen in 1980, recording one eponymous album before returning to his blues-rock roots. In addition to working with artists like Greg Lake, B.B. King, Jack Bruce, Ginger Baker, and the Traveling Wilburys, Moore released a steady stream of solo albums throughout the last three decades, scoring his biggest U.S. hit with 1990’s breakthrough Still Got The Blues, which featured contributions from Albert King, Albert Collins, and George Harrison, among others, giving Moore his widest exposure. His last studio album was 2008’s Bad For You Baby.