Haken are an English progressive metal band. Their sound is very heavy, but contain some very complex progressions, and no screaming vocals. It is not normally a genre I listen to on a regular basis, but this particular album has had a lot of staying power. Its complexity and (make no mistake) heaviness make for excellent repeated listenings. In fact, I often use it for my long runs and workouts. Highly recommended. Above is Vector, their latest album.