Unquestionably the most influential guitarist to emerge from the late-'70s/early-'80s U.S. hardcore/punk movement was Black Flag's Greg Ginn. Never afraid to incorporate other musical styles into his playing (namely jazz fusion and Black Sabbathy heavy metal), as well as squealing feedback from his amplifier, Ginn's guitar also served as a major ingredient to the Black Flag sound as he was the only original member to remain in the group from its formation until its demise. Influenced equally by the Grateful Dead and the Stooges, Ginn formed Black Flag in 1977, but the group didn't really start to make a name for itself until Ginn set up shop in Hermosa Beach, California in early 1979, where he began running an electronics supply business. It was during this time that the phrase "SST" was coined (an abbreviation for Solid State Transmitter), which would eventually be used for the name of Black Flag's record label. Although members came and went at a steady rate (including singers Keith Morris, Ron Reyes, and Dez Cadena), Black Flag prevailed, building a large and loyal following on the strength of their explosive live show, EPs/singles (including such classics as Nervous Breakdown and Jealous Again), and an appearance in the cult classic L.A. punk documentary The Decline of Western Civilization. Ginn also began to favor a Plexiglas "Dan Armstrong" guitar, which would soon become a trademark of sorts for both him and the band (despite eventually becoming covered with black tape).