Bullhead was a breakthrough for the Melvins. The leadoff song, “Boris,” became an anthem for the trio, symbolic of their doom-laden ethos. An unrelenting slog, glowing with molten distortion, “Boris” is the sort of thing that resonates through the listener’s marrow long after the music has stopped. The rest of the album is almost as wild. “Anaconda,” “Ligature,” and “If I Had an Exorcism” are titles that perfectly represent the music within. This is playing that draws inspiration from ancient biology and the great mysteries of nature as much as the history of rock and roll. At the same time, Bullhead functions as a badass rock record. “Zodiac” and “Your Blessened” rid heavy metal of all corny gimmicks, leaving only the music’s black, beating core. Compared to conventional rock music this sounds like drudgery, but listeners should pay closer attention. There is a magisterial air to these performances. The uninitiated might want to start with “It’s Shoved.” One of the Melvins’ most tuneful moments, Nirvana later lifted the riff for “Milk It,” from In Utero.