Bob Ludwig, for me, is the final boss of “make it hit”: cutting lacquers at A&R in the late ’60s, shaping the 1970s at Sterling Sound, the 1976–1992 Masterdisk era, then building Gateway Mastering in Maine (founded 1992) before retiring in 2023. His mastering fingerprints run from classic rock to metal to modern pop—Led Zeppelin and Lou Reed through Metallica, Nirvana, Tool, and Daft Punk.