Here's a link about rights and a song that I'm thinking of using, a possible replacement for Zabriskie Point.
http://www.loc.gov/folklife/cg.html
I've collated all Documenta 11-related entries in one page, which I'll keep updated. There's been a steady/increasing number of Google searches for Documenta and participating artists; rather than add a new index ("Shows I've seen" or something), I'll try this compilation page idea.