Bob 53 says: "It's the soul of the music saying 'I'm alive'." Wow. That's really beautiful. I'd never thought of it exactly like that, although I do like a little bit of occasional string noise to confirm that the music is being played by living, breathing human beings and not a synthesizer. I just don't like it when the noise overwhelms the music. After all, a song's soul is bigger than the person playing or singing it.