The mechanics behind basic delay are simple: Play a note or chord into an audio-storage medium, then get that device to play that sound back to you — either once or multiple times — after whatever amount of time makes you happy. Of course, people have improved upon this simple formula, taking delay to new depths and heights, and often including an infinite assortment of types and combinations in one pedal.

For Tool, music and imagery are inextricably united—which is why the group is reissuing its 1992 debut EP, Opiate, in an extremely limited edition with new artwork and collectibles. Adam Jones explains.

The Ocean is a German progressive metal band that began in 2000 and steadily built up a reputation on the strength of their creative experimentation on early albums like Fluxion, Aeolian and Precambrian. Subsequently, they took upon the task of a massive double concept album, released in two parts as Heliocentric and Anthropocentric in 2010.

Malcolm's really underrated. He makes the band sound so full, and I couldn't ask for a better rhythm player. Sometimes I look at Malcolm while he's playing, and I'm completely awestruck by the sheer power of it. He's doing something much more unique than what I do-with that raw, natural sound of his. People like Malcolm, Steve Cropper, Chuck Berry and Keith Richards-they're all doing something better than the rest of us.