A Perfect Circle was formed by Billy Howerdel.
Howerdel spent several years sound engineering for New Jersey artists and further worked as a guitar technician for numerous others, which, before forming A Perfect Circle, included Faith No More, Fishbone, David Bowie, The Smashing Pumpkins, Nine Inch Nails, Guns N' Roses, and Tool
 While similar to Tool in intensity and melancholy, A Perfect Circle is less dark and more melodic, with a theatrical, ambient quality that incorporates occasional strings and unusual instrumentation

