Max Brooks, despite my past disagreements with him, got it right when he called attention to the Primary Enticement Mechanism (PEM). Once humanity counter-attacked, it seemed each group of survivors independently determined that loud, pulsating music served two purposes: The first, stated reason would be to lure the undead into a kill zone. The second, but most important reason was to psyche you up.
I have my own, personal playlist from the time that I served as a Sky Watcher. Whatever the artistic merits of these songs, they still get my blood up. Each song on the list has a personal story behind it. I will relate those as time allows.