1. Noisecore is a synonym for noise rock, an extremely fast and volatile combination of punk rock and noise music. Examples include Lightning Bolt and Melt Banana.
2. Noisecore can refer to grindcore (an extreme combination of metal and punk) combined with noise music. This style focuses on speed and chaos rather than musicianship or structure. Examples include Anal Cunt and Gore Beyond Necropsy.
3. Noisecore is occasionally used to describe hardcore techno, an electronic music style that developed in the 1990's in New York, Rotterdam, and Newcastle. Examples include Anabolic Frolic and Ethos.
Noisecore is not related to any subgenre of metalcore, or metalcore itself. Some bands incorrectly referred to as noisecore such as Dillinger Escape Plan and Coalesce are not influenced by noise music and do not incorporate it into their respective sounds at all.
John Doe: I heard this band from Japan kind of sounds like Merzbow combined with punk, but on speed.
Jane Doe: Huh, they're probably noisecore.
John Doe: This band's so fast and crazy. They sound like a combination of Napalm Death and flaming motorcycles.
Jane Doe: Wow, sounds like they're noisecore.
John Doe: Are you going to the rave tonight? I hear the DJ plays classic detroit techno, but really fast and he uses distorted industrial beats.
Jane Doe: I'm not going. I hate noisecore.