Shawn noted this already but I want to elaborate a bit on this exciting new edition of the Liber Usualis -- an ingenious product of the old Solesmes monastery that has never been superseded and remains an invaluable book for all singers.
It contains of course all the Graduale chants and a Kyriale for the congregation but there is much more here, including vast numbers of office hymns, the readings under the old calendar, the order of Mass, and very clear instructions on rubrics, musical technique, and so much more.
So this reprint is very exciting, specifically because it is the 1962 edition. This is the edition that the CMAA has already made available online. Now you can get it in print. You pay $150 for it, but it is fully 2,000 pages, you get a lifetime of use out of this book.
It was an is the accumulated knowledge of 2,000 years of musical progress in Church liturgy, not to mention great progress in publishing and typesetting techniques, and awe inspiring in every way. Even if you don't think you would use it now--and people who work within the OF people that they will not--the longer you own it, the more you end up using it, simply because it somehow, incredibly, contains just about everything.