Liber Usualis (1961)

Hear ye! Hear ye! The ubiquitous chant book for the Traditional Roman Rite, the Liber Usualis (1961 edition) is now available for free download online from the good folks at CMAA.
No more excuses of expensive Libers from Novus Ordo parishes wanting to implement Pope Benedict XVI's motu proprio Summorum Pontificum.

What's the difference between the Liber Usualis and the Graduale Romanum?

This question has plagued yours truly for some time and Deo gratias, this resource came just in time to the rescue. See the List of Uniform Titles for Liturgical Works of the Latin Rites of the Catholic Church.

This list gives a comprehensive listing of pre and post-conciliar liturgical books in the Latin rite, including the rites of the religious orders and other such variants.

Thanks to NLM for the info.

Liber Usualis in modern notation

Just found this resource for a Liber Usualis in modern notation rather than the usual Gregorian notation. Pretty useful for those who are only familiar with modern musical notation. Do consider donating via Paypal to this elderly guy who took great pains in scanning up these pages, if you decide to print out these pages and use them in your singing. He has graciously provided yours truly with many pieces in SATB bourdon and fauxbourdon versions, too. I'd be most happy to send some of these to whoever is interested.