So far we've had (among many others:)
The Origen of Species
the Rig Veda
The decline and fall of the Roman empire
Changing bodies, changing lives.
and a choral song in French that nobody could pronounce.
Oh, and the girl whom theCSO sent to act out "Godel, Escher, Bach: An Eternal Golden Braid" has been up there for like 20 minutes.