I can't believe I'm giving this idea away - I'm a horrible friend...
a friend of mine (who doesn't write musicals or shows or anything, so I guess it's not really horrible cause she couldnt' do it even if she wanted to) was dying to see/do a musical inspired by that book/website/magazine called Found - have you heard of it?
I think it's just www.found.com (not sure - might be foundmagazine.com or something) but it's basically a book (and then I think turned into a magazine adn then a website) that you can get at Borders for like $10-14 of things people find and send in: pictures, notes, stuff like that. They title them, and do a mini-write up of how they found the item.
Things like notes to lovers, pictures drawn by kids - it'd be more of a song cycle type thing and just inspire individual songs more than anything but...it's great to try to create a backstory for these moments or items or pictures.
There is one that's like, a note left on this guys' car - obviously left for someone else, someone mistook his car for thier boyfriend's, and wrote this whole angry letter about "you said you were through with her but then why are you here at her house!!!!???? I hate you I hate you I hate you" (she writes "I hate you like, a bazillion times) and then it says, and I kid you not, "Ps. call me tomorrow" - just trying to imagine someone who has that kind of outlook on what they deserve in a relationship - that they're already willing to forgive when forgiveness hasn't been asked...
stuff like that and little things like a note a child wrote that says "I Love" - neat that it isn't completed. The person who sent it in was just like "I like that idea: not "I love ice cream or school or my dog" but just that I, as a person, Love.";
Evaluations from a college course in which the person wrote something along the lines of "the class was so useless it spawned a hate in me that has not only effected me, but my loved ones and people I have yet to meet, until it finally grew to the piont that I hated myself for being there"...
There's neat stuff - some moving, some funny, but all things that I think would be great to just inspire ideas for something loosely intertwined (ie: songs for a new world - all having that moment theme tying them together) and something more like a song cycle or inspiration for individual pieces.
besides that...nothin'.

Hope you check it out and maybe it helps!
feel free to message me if you need direction to the website or more info
If I show you the darkness I hold inside, will you bring me to light?