This story reminds me of a quote attributed to Lennie;
If Charlie Parker wanted to invoke plagiarism laws, he could sue almost everybody who's made a record in the last ten years. - Lennie Tristano
Do all of the musical ideas possible exist and are they just waiting for someone to discover them and stake their claim? Or are there infinite combinations? Have there been cases of truly parallel developments of melody? Does the consequence of copyright law encourage all artists to put out as much material as possible, without regard to quality, to improve their chances of snaring that killer melody that everyone wants to license? And offset their chance of being sued for infringement themselves?
Sucks to have to be so careful of your every note.
Time to go out and patent that peanut butter and jelly sandwich.