Bassist Paul D'Amour left Tool in 1995 and was replaced by Justin Chancellor that same year. D'Amour made it clear in a 2020 interview with Guitar World that his decision to leave Tool was due to their lethargic creative process, and his drive to make more music.
"I wish it had been a better vehicle for me to create in, but it just wasn't," said D'Amour at the time. "Their creative process is excruciating and tedious, and I guess I never felt the desire to play a riff 500 times before I can confirm that it's good; that's why it takes them eight years to write an album.
"I always wanted to do other things, and it felt like I was too much in a box with that band. They're set up where the bass player does the bass part and the guitar player does the guitar part and so on. I couldn't be stuck in that paradigm– it's too stifling. I'm not just a bass player; I'm a creator, I wanted to have a bigger role, and it just wasn't happening in that situation. In the end, I knew leaving was the right decision."
But what was the transition between D'Amour and Chancellor like? According to D'Amour in an interview with Bass Player, it was very friendly and involved D'Amour showing Chancellor everything he was doing. D'Amour said as he was leaving Tool, the band was well into their Ænima sound, and he passed that on to Chancellor.
"I feel like we created a sound that was blossoming at the time of Ænima. And to their credit – and I'm not shitting on Tool; I hope I don't come across as being Mr. Sour Grapes at all because I'm quite happy with my life, my choices, and what I do creatively.
"So, yeah, I'm sure it would have been different. Basically, when I left the band, Justin [Chancellor] was my friend; I invited him to my house, sat on my couch with him, and showed him how to play the songs.
"I showed him how I got all my sounds, my octave pedals, Whammy pedals, my phasers, and how I approached these different things. I honestly wanted him to be very successful because he seemed pretty nervous about doing it. And so, like I said, that sound already existed."
Despite his absence, D'Amour is still credited as a songwriter for the songs "Stinkfist", "Eulogy", "H.", "Pushit", and the title track on Ænima.
