I think it's because music conjures up our sensory memories of good times, or sad ones too. Like the scent of cookies baking, music pulls up our memories and feelings. And for the good memories awesome music pulls up - who wouldn't like the fantasy of feeling at our best and being with a sexy musician and no worries? :)
Your books are one of my addictions Jennifer! Oh and I secretly love Californication. It's so raunchy, but I keep hoping Hank will be redeemed somehow. I too love Hawaii 5 - 0, more than I thought I would and I'm so happy they "recycled" the theme music! :)