Steppenwolf

Proto-metal is the late-1960s hard, heavy strain of rock that crystallized the sonic vocabulary later codified as heavy metal. It bridges blues-rock, garage rock, and psychedelic rock with louder amplification, thicker distortion, and riff‑centric songwriting. Musically, proto-metal emphasizes power-trio or organ/guitar lineups, pentatonic/blues-derived riffs, power chords, and aggressive, often fuzz-saturated tones. Vocals can range from soulful shouts to theatrical wails, and rhythms often push straight 4/4 grooves at mid-to-up tempo with a palpable sense of weight and drive. Historically, it includes bands whose heaviest work predated metal as a named genre, as well as early albums by future metal standard-bearers. Its sound laid the groundwork for the timbre, riff language, and attitude of heavy metal and, by extension, numerous metal subgenres.