When I'm feeling slack in the mind, but I have something that I have to do, Death Metal calms me and helps me concentrate. Especially this ^ band.
Does anyone else experience this? 
What kind of music helps you focus?
						
					
					
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	Pendulum and Prodigy. Also, anything like 30 Seconds To Mars, Linkin Park, Foo Fighters and even some stuff like Halo OST's.