Just Hear It is a free site where you can enter the name of any song and be presented with a list of links. Click a link and you are listening to the tune.
I tried the site with everything from classical selections to pop and even tried titles of young concert band literature all with great success. In many cases, the results include YouTube videos.
The site is in beta right now, so who knows how long it will be totally free and what the capabilities will be when the site is no longer in beta. For those of us looking for a quick recording, even of something obscure, this site is a pretty significant reference.