Well I have to point out a flaw in this article.

I frequently listen to people playing on the street -- I just don;t stand there and watch them. I might be sitting a bit down the platform or behind them but I do enjoy the music (sometimes -- sometimes I wish they would stop!).

If I enjoy it, I do drop money in before leaving. The point is, the musician might not ever SEE me. Because it's not a concert hall, it seems rude to stop and stare at the guy.