This collection of the psalms was originally published in 1981 (reprinted 2012) by the Monks of Solesmes, after the reform of the Benedictine office approved in 1977. The book contains the full text of the 150 psalms along with hymns from the Old and New Testaments, all in Latin. The order of the psalms is that according to the Rule of St. Benedict, which deviates very little from the numerical order. There are four "schema" or plans, that allow for great flexibility in the order of service. Fin ally, there are certain liturgical provisions from the Rule, which are clearly laid out in this useful chant volume.