From a sporting perspective I don’t listen to music before games. I do this for two reasons: 1) I play a team sport and I like to get into the team spirit in the change rooms before a game. I can’t do that if I am listening to music on headphones; 2) My musical tastes are not shared by many, and I normally don’t find other peoples music gets me in the right mind set.
But I do understand that other people like music. I have found that before big games people get quite stressed and this can permeate through a change room. So in these cases music can be a welcome strategy to calm nervous people down. I just tune it out (unless I like it!)
If I am training on my own (ie: riding, running, walking) I love listening to music. I just don’t train on my own very much!