Out of Los Angeles in 1990, Tool came together when vocalist Maynard James Keenan linked up with guitarist Adam Jones, bassist Paul D'Amour, and drummer Danny Carey. D'Amour was later replaced by Justin Chancellor, locking in the lineup that would define the band's sound for decades. What they built together was something genuinely hard to categorize — dense, polyrhythmic progressive metal that demanded your full attention and rewarded repeated listens in ways most rock bands simply couldn't pull off. Carey's drumming alone set a new benchmark for technical complexity in heavy music.
Their 1996 breakthrough Aenima put them on the map in a big way, but it was 2001's Lateralus that cemented their legacy. Built around the Fibonacci sequence and packed with shifting time signatures, it felt less like an album and more like an experience. Fear Inoculum arrived in 2019 after a 13-year gap and still debuted at number one, proving their fanbase doesn't just stick around — it borders on devotion. Tool occupies a rare space in rock where artistic ambition and genuine heaviness coexist, and their influence on progressive and alternative metal continues to echo through virtually every band willing to push past the four-minute song structure.