The fifteenth Sunday after Pentecost is of semi-double rite and its liturgical colour is green. This year it is the fourth Sunday of September.
At Vespers yesterday afternoon the antiphons and psalms of Vespers for Saturday (Pss. 143, 144, 145, 146 & 147) were sung. The chapter was O Altitudo and the Office hymn was O lux beata Trinitas. The antiphon on the Magnificat was Adonai Domine for the Saturday before the fourth Sunday of September. After the collect of the Sunday the Suffrages of the BVM Sancta Maria succurre etc, the Apostles Petrus Apostolus etc, of the Patron and lastly for peace Da pacem Domine were sung. At Compline the Dominical preces were sung.
At Mattins the invitatory is Adoremus Dominum and the Office hymn is Nocte surgentes. In the first nocturn (Pss. 1, 2, 3, 6, 7, 8, 9, 10, 11, 12, 13 & 14) are sung. The lessons are the Incipit of the book of Judith. These lessons are the same as in the post-Clementine editions. In the second nocturn (Pss. 15, 16 & 17) the lessons are from St. Ambrose on Elias and fasting. These are significantly longer than those in the modern books. The text of the fifth and sixth lessons is not found in the modern books. In the third nocturn (Pss. 18, 19 & 20) the homily is from St. Augustine on St. Luke's Gospel. The entire seventh lesson is absent from modern editions: Miracula Domini nostri ... quam suscitare iterum moriturum. The eighth lesson is significantly longer than that found in modern editions. The ninth lesson is the same as that found in the modern books. The Te Deum is sung.
At Lauds the Sunday psalms (Pss. 92, 99, 62-66, Benedicite , 148-49-150) are sung. The Office hymn is Ecce jam noctis. After the collect of the Sunday the the Suffrages of the BVM Sancta Maria succurre etc, the Apostles Gloriosi principes etc, of the Patron and lastly for peace Da pacem Domine etc are sung.
At Prime (Pss. 53, 117, 118i & 118ii) Quicumque is sung as are the Dominical preces.
Mass is sung after Terce. The Gloria is sung, the second collect is A cunctis, the third collect is chosen by the Dean or Rector of the place. The Credo is sung as is the common preface.
Vespers are of the Sunday (Pss. 109, 110, 111, 112 & 113). The Office hymn is Lucis creator. After the collect of the Sunday a commemoration is sung of the following feast of SS Eustace and Others followed by the Suffrages of the BVM Sancta Maria succurre etc, the Apostles Petrus Apostolus etc, of the Patron and lastly for peace Da pacem Domine . At Compline the Dominical preces are sung.