Thanks for the tip about using grungy brushes Kyle. I'll give that a go. I'm also considering tearing a small section of the paper, and mabye a few ink-spots.
Thanks for your comments mscallisto. Yes I did use the liquify filter to bend the lines of the music score. I think I'm going to redo that layer though. I think there's too many lines of music in the picture. I like the effect where I've really warped the section that goes around his eye and above his eyebrow, so I'll probably cut the number of lines of music below that to about 3, and be a bit less subtle with the liquify tool.
I'll post another one up when I've made some changes.
Thanks a lot for your time guys.