I'm with Doug. I came to GT with a fairly solid guitar background. I wanted to learn the great classic rock guitar songs performed by my guitar heroes. I also wanted to get in their head and follow why they did what they did. It literally changes the way you listen to music, at least for me. It also allows me to understand a bit more about the genius behind the music. 
when MANY of these songs went away, it was a bit heart breaking to see.