Heart and Soul may be extremely annoying, but there has been a response to it for over a year now. If you ever find someone playing it, walk up to them and start singing the chorus of Friday (or any part of Friday, for that matter. It's the same chords all the way through.) They match up perfectly if you sing these words on these chords:

Friday, Friday, gotta get down on Friday.
Everybody's looking forward to the weekend.
Friday, Friday, getting down on Friday.
Everybody's looking forward to the weekend.
Partying, partying, yeah. Partying, partying yeah. (This part will be a bit rushed.)
Fun, fun, fun, fun, looking forward to the weekend.

There you go, a sure-fire way to ruin that song forever. Hopefully.
P.S. You can also do this to the beginning of Bohemian Rhapsody, but why would you want to do that?