Ronnie Montrose was never as famous as his peers. He is the lost ‘70s guitar god — the massive-sounding riff facilitator on the most memorable Edgar Winter Group release (1972’s They Only Come Out at Night) and one of the strongest eponymous debuts no one ever talks about, 1973’s Montrose.

Before his death this weekend (initially reported as the result of prostate cancer, his website states he “chose his own exit”), the principal reason anyone mentioned Montrose was because it served as the launching pad for Sammy Hagar’s mainstream career as a vocalist. But the strength of the band was always the towering, reverberating heft of Montrose’s guitar and the production of Ted Templeton, who’d later use the Montrose sonic template to create the signature sound of Van Halen. According to many who worked alongside him, Mr. Montrose was an unusually serious, anti-glam perfectionist who was so inflexible about music that he was sometimes difficult to work with: When Hagar tried to convince him to put on a more commercial stage show in the mid ‘70s, Montrose essentially stopped talking to him and allowed the original lineup to implode. (“He had a lot of anger inside him,” Hagar wrote in 2011. “He could have been in Metallica or something like that today. He shut me out.”) However, the passage of time has validated Montrose’s single-minded approach; though he never earned the personal adulation of Ted Nugent or Brian May, his music remains equally present within the modern landscape of classic rock radio. Montrose was 64.