quodlibet

Concise Oxford English Dictionary © 2008 Oxford University Press:
quodlibet /ˈkwɒdlɪbɛt/

▶noun

• 1 archaic a topic for or exercise in philosophical or theological discussion.

• 2 literary a light-hearted medley of well-known tunes.

– derivatives
quodlibetarian /-bɪˈtɛːrɪən/ noun.

– origin ME: from L., from quod ‘what’ + libet ‘it pleases’.