I think it really depends on both the music and the person. For me personally, I can only really concentrate with music on, preferably on headphones. This way I

I think it really depends on both the music and the person. For me personally, I can only really concentrate with music on, preferably on headphones. This way I can really close down from stuff happening around me. On the other hand, if the music is very lyrics-based, I'll usually start focussing on that instead. So for me, the amount of lyrics in the music I listen at a given moment is inversely proportional to the level of concentration I need ;)