This link lists the psalm schemas for the 4 most common ones, the ones in the Thesaurus Litgurgiae Monasticae.
gregorianbooks.com/gregorian/www/www.kellerbook.com/SCHEMA~1.HTM
Scroll down the page to Section 1: 1970 to Present.
Note that Schema A is the traditional Benedictine psalm schema, essentially unchanged since the time of St. Benedict; however the example shown on the link shows only one of the possible variants for the redistribution of the psalms of Prime, if Prime is abolished. Ad libitum, monasteries using Schema A may retain Prime and a few do apparently. For those that do, on the same page a bit further up you’ll see the traditional pre-Vatican II Benedictine Office for the layout (essentially also copied by the Carthusians).
Schema B is the only one that in essences fulfills the Rule’s admonition that if a monastery prefers a different schema than the one St. Benedict defines, they may do so, as long as all 150 psalms are said in a week. This is the schema used at the abbey to which I’m attached as oblate. In our abbey, Lauds, Vespers and all the hymns are chanted in Latin.
The other two schemas are essentially 2-week psalters. We must keep in mind that at the time of St. Benedict no monasteries had external charges as many do now (colleges, supplying parishes).
I’ve also been to monasteries that have a hybrid schema. One popular one is to use the 4-week LOTH for Vigils/Lauds/Mid-day prayer (one I’ve been to combines Vigils and Lauds into one office of Matins); these Offices are on a 4-week cycle and in the vernacular; Vespers and Compline are taken from the old Monastic antiphonary and in Latin and are on a one-week cycle.
I was also at Sant’Anselmo in Rome a couple of times for extended periods, it’s the main Benedictine teaching college. Lauds is combined with morning Mass (during the week, separate Office on Sundays), in chanted in Italian, and from the 4-week LOTH, as is mid-day; Vespers and Compline are in Latin Gregorian chant, from the old Antiphonary, but on a two-week cycle. Again this is a working college, students from all over the world, and many profs and students coming and going to courses outside the monastery in different locations in Rome, so it’s kept relatively simple. Office of Readings is done in private in cell. Interesting note, it’s a very pleasant atmosphere, much less formal than my Congregation (Solesmes) and when visiting I was invited to sit in choir with the monks for all Offices as well as the Mass, something really special!
Schema B is reportedly the most popular schema in the Benedictine Confederation because it meets the letter of the Rule but is much lighter than the schema devised by St. Benedict, with 150 psalms recited per week without repetitions rather than 250 with repetitions. Some things I like about it but in terms of actual psalm placement, the 4-week LOTH actually comes closer to the old Benedictine tradition than Schema B. For example, almost all the Office of Readings psalm are from Vigils of Schema A, and the last 2 weeks of the LOTH take almost all the psalms from the Monastic cursus for Vespers, and lastly, the LOTH allows one to use psalms 4, 90 and 133 for Vespers every day, again from the Monastic tradition. Schema B proposes a way to do that but then it becomes a 2-week schema, and no longer respects the letter of the Rule.
