The Antiphonale Monasticum is the essential book for the monastic choir. It contains all the texts and chants for the day hours of the Divine Office in Latin. This edition is a reprint of the classic 1934 edition of the Antiphonale published by the monks of Solesmes and used in Benedictine monasteries throughout the world before Vatican II.
Besides providing the texts and chants of the Office, there is a useful appendix with instructions on the different psalm tones used throughout.
This does not contain an English translation.