10 Most Important Member Changes In Rock Music History

10. Justin Chancellor Replaces Paul D’Amour - Tool

American rock band/professional fan-frustraters Tool first formed in 1990 as a four-piece. Maynard James Keenan was the singer, Adam Jones was on guitars, Danny Carey was on drums, and Paul D'Amour was on bass.

The group's first album Undertow was a decent record that stood out nicely against the backdrop of grunge and pop punk. However, the band really took things to new heights with their next release - the much-revered Ænima.

In all this time, has anyone worked out how to actually say that word? Or what it means? Didn't think so.

Someone who certainly won't know is D'Amour, as he left the band before it was recorded. He claims that he wanted a bigger role in the group and that he didn't want to get stuck playing bass.

Thankfully, a man who was more than happy to pluck the four strings was Justin Chancellor, D'Amour's replacement. Chancellor quickly became a key part of Tool's set-up and the band switched around their style to include more of his bass work in their songs.

Considering how important that sound is to Tool these days, this was 100% the right call.