Links mentioned at the Teaching Shakespeare Institute:

Creative Commons:  http://search.creativecommons.org/ ; YouTube, Google

Global Shakespeares:  http://globalshakespeares.mit.edu/#

Guide to Med/Ren instruments: http://www.music.iastate.edu/antiqua/instrumt.html

Choral Public Domain Library:  http://www.cpdl.org/

Classical Music Online:  http://classical-music-online.net/

Librivox:  https://librivox.org/

Map of Early Modern London:  http://mapoflondon.uvic.ca/

English Broadside Ballad Archive:  http://ebba.english.ucsb.edu/

Bodleian Library of Broadside Ballads:  http://www.bodley.ox.ac.uk/ballads/

A Short History of Books:  http://www.designhistory.org/BookHistory_pages/Incunabula.html