This reminds me of a question that was posed on NPR's music blog last year sometime. They asked readers for their Six Song Soundtrack to their lives. It was fun to think about that, and I kept the list I sent in:
Let It Be (Beatles) - First song I remember hearing in life, and was very comforting at a young age.
Somewhere Over the Rainbow - Have always loved the movie, but the song itself resonates with me because I spent much of my youth looking for that better, happier place.
Roam (B-52s) - My dad and I did a big road trip every summer growing up, and as an adult I absolutely love traveling and exploring.
Sweet Transvestite (from Rocky Horror Picture Show) - OMG, I could write a book about the various ways this song (and movie) has touched my life. Suffice to say, the movie helped me accept being gay, and this song in particular ties to a very specific and hugely pivotal time in my life when I was really coming into my own. Buy me a drink and I'll tell you all about it. (No, I'm not a transvestite.)
Wrecking Ball (Bruce Springsteen) - I couldn't put a list like this together without the Boss. And this song both encapsulates my mixed emotions about the state of the world, and also speaks to a more personal desire to sometimes just tear my life down and start over. Plus, seeing him do it live was one of the most spiritual experiences of my life.
Every Little Thing (He) Does (Shawn Colvin) - My anthem for the future. I will dance to this song at my (thus far fictional) wedding.
I'd love to hear a little more about why you have put certain songs on your lists!
