The feast of the Immaculate Conception of the BVM is a Double of the First Class with Octave. The colour of the feast and Octave is white. The feast takes precedence over the second Sunday of Advent. The feast was prepared for by a Vigil, commemorated in the Office of St. Ambrose yesterday.
At Vespers yesterday afternoon the antiphons Tota pulchra etc were sung with psalms 109, 112, 121, 126 & 147. The Office hymn was Ave maris stella. After the collect of the feast a commemoration was sung the Sunday. At Compline Te lucis was sung with the Doxology Jesu tibi sit gloria and to the melody proper to the Incarnation.
At Mattins the invitatory is Immaculatum Conceptionem Virginis Mariae celebremus: Christum ejus Filium adoremus Dominum and the Office hymn is Praeclara custos Virginum. In the first nocturn the antiphons Admirabile est etc are sung with psalms 8, 18 & 23. The lessons are taken from the third chapter of the Book of Genesis. In the second nocturn the antiphons Diffusa est etc are sung with psalms 44, 45 & 86. The lessons are from a sermon of St. Jerome and and the sixth lesson is from the acts of Pius IX. In the third nocturn the antiphons Sanctimonia et magnificentia etc are sung with psalms 95, 96 & 97. The homily is from St. Germanus on St. Luke's Gospel. The ninth lesson is of the Sunday, a homily from St. Gregory on St. Matthew's Gospel. The Te Deum is sung.
At Lauds the antiphons Tota pulchra etc are sung with psalms 92, 99, 62, Benedicite & 148. The Office hymn is O gloriosa Virginum. After the collect of the feast a commemoration is sung of the Sunday.
At Prime and the Hours the antiphons Tota pulchra etc are sung with the festal psalms. The hymns have the Doxology Jesu tibi sit gloria and the melody of the Incarnation. At Prime (Pss. 53, 118i & 118ii) the versicle in the short responsory is changed to Qui natus es de Virgine and the lectio brevis is Signum magnum apparuit.
Mass is sung after Terce. The Gloria is sung, the second collect is of the Sunday. The Creed is sung, the preface is of the BVM and the last Gospel is of the Sunday.
At Vespers the antiphons Tota pulchra are sung with the psalms of the BVM. The hymn is Ave maris stella. After the collect of the feast a commemoration is sung of the Sunday.
In the 'liturgical books of 1962' the feast has been stripped of both its Vigil and Octave. At Compline and the Hours the Doxology is not changed and the hymns are not sung to the melody for hymns of the Incarnation. At Prime the lectio brevis is of the season, Domine, miserere. At Mass the last Gospel is In principio. In the stage of the modernist reform immediately prior to the 'liturgical books of 1962', 1956-1960, the feast did not take precedence over a Sunday and so was moved Monday, 9th December, as was the case in 1957.
From the excellent archive of the 'Catholic Herald'