In a lot ways, the use of a compressor in a metal context is redundant, because a highly distorted tone is inherently very compressed to begin with. But any time you are playing a clean or low/mid gain type of sound, a good compressor will make your notes pop a great deal more. Much of the sustain that you would get from the gain can be replicated on your clean tone with compression, allowing your guitar to both cut through and ring out.
Tosin Abasi and Keith Merrow got together to demonstrate this concept using the Seymour Duncan Vise Grip pedal at Merrow’s home studio. Tosin was probably the perfect dude to do this because he uses a great deal of clean and low gain sounds across a gigantic pitch range, and a compressor is something he probably uses a fuck ton.
Come for the thump, stay for the real talk.