The more I listen to music, particularly metal, the more I notice sounds which don't sound quite 'right' and creates feelings of tension. Yet they still sound cool. The beginning of Meshuggah's song "Future Breed Machine", Norma Jean's "Memphis Will Be Laid To Waste", and "Panasonic Youth" by The Dillinger Escape Plan are prime examples of that tension I feel when I hear their music.
Here are the songs that I mentioned earlier. FULL OF TENSION!!!