I think this can be interpreted two ways...it can mean songs whose titles and words describe your life & it's events, feelings, etc., or it can just be songs that were significant at some point in your life.
I decided to take the easier route on this and just pick songs that stand out from various points in my life, and because I tend to define the first half of my life in terms of what educational level I was in, I've narrowed it even further to those. And to make it even easier on myself, rather than try to figure out if a song "defined" that part of my life, I've just picked the first song (or in some instances band) that popped to mind for that period of my life.
So here goes....
Delta Dawn - Tanya Tucker
The only reason I can think of that this was the first song to come to mind when I think of my elementary school years is that we used to sing this song on long car rides, so I have memories of singing this with my whole family. It's one of the few songs (besides "Found a Peanut") I can remember my father ever singing.
Mountain Music - Alabama
I'm not sure if I was in 7th or 8th grade when this album came out, but my best friend and I loved this song in particular and played it over and over.
Troubled Child - Journey
Of course any mix tape of mine has to contain a Journey song, and this is the album that came out during my high school years. As is common for me, my favorite song on an album is often not one that is regularly played on the radio, and this is one of my favorites from this one. The entire album of course was played until the cassette tape (yes we still used those then) was stretched.
Only the Good Die Young - Billy Joel
This was pretty much the theme song for my college years. We thought we were wild and crazy and breaking all the rules...we weren't...but it felt like it right? I can't hear this song without thinking of my college roommate and some great memories.
Let Her Cry - Hootie and the Blowfish
Back when I was in law school, Hootie and the Blowfish was still a bar band. My boyfriend at the time lived in Columbia, SC and was friends with the band, so we traveled all over North and South Carolina, and sometimes Virginia and Georgia too, on weekends following them from bar to bar. We never had to pay a cover charge because we were always on the guest list, and often crashed wherever they did for the night. Maybe I'll tell some of my more humorous (and a few embarrassing) Hootie stories someday....or maybe not.
So there you have it...the soundtrack of my life, at least until age 24 or so.