SEQUENTIA (Prosa; Eng. Sequence, or Prose). A Hymn of peculiar structure, sung on certain Festivals at High Mass, after the Gradual, Versus, Tractus, and Alleluia.

The Sequentia owes its name to its position in the Mass; in which it appears, as the continuation, or sequence, of the long series of Verses and Antiphons, interposed between the Epistle and the Gospel. In the Middle Ages it was called a Prose; because, though written for the most part in rhymed Latin, and frequently with perfect uniformity of rhythm, the cadence of its syllables was governed, not, as in classical Poetry, by quantity, but by accent—a peculiarity which deprived it of all claim to consideration as Verse of any kind. Its introduction into the Liturgy is generally supposed to date from the 9th or 10th century. In the 11th and 12th it was very extensively used; and many of the most beautiful specimens we possess were written by the great Hymnologists who flourished during these productive periods. Mediæval Office-Books contain innumerable Sequences, of striking originality; but, at the last revision of the Roman Liturgy, by direction of the Council of Trent, the greater number of these were expunged. Five, however, were retained, in the revised Missal; and these five occupy a very prominent position in the Services in which they are incorporated, as well as in the history of Ecclesiastical Music.

1. The Sequence appointed for Easter Sunday is 'Victimæ paschali,' the oldest now in use, dating, in all probability, from the loth century.

2. Not very much less ancient is that for Whit-Sunday, 'Veni Sancte Spiritus'; in rhymed triplets of Trochaic Dimeter Catalectic, written, about the year 1000, by King Robert II. of France, and called, by mediæval writers, 'The Golden Sequence.'

3. For the Festival of Corpus Christi, S. Thomas Aquinas wrote the celebrated Sequence, 'Lauda Sion,' which is generally believed to date from about the year 1261.

4. The 'Stabat Mater,' sung on the 'Feasts of the Seven Dolours of Our Lady' (the Friday in Passion Week, and the Third Sunday in September), is generally referred to the end of the 12th, or beginning of the 13th century. The name of its author has not been certainly ascertained: but Daniel,[1] after much patient investigation, attributes it to Jacobus de Benedictis.

5. More justly celebrated than any of these, is the 'Dies iræ,' written, during the latter half of the 12th, or beginning of the 13th century, by Thomas of Celano, and sung in the 'Requiem,' or Mass for the Dead. In the triple Stanzas of this wonderful Poem the rhymed Latin of the Middle Ages attained its highest perfection; and, though the 'Stabat Mater' is frequently said to be second only to it in beauty, the distance between the two is very great. No Latin hymn has probably been so often translated.

The Plain Chaunt Melodies adapted to these five Sequences, in the Gradual, differ from Hymn Melodies chiefly in their continuity. Each Melody is founded, it is true, upon certain fixed and well-marked phrases; but these phrases are not mechanically repeated, as in the Hymn, to each successive Stanza of the Poetry. The authorship of these Melodies is indiscoverable. They were probably composed by the Poet, simultaneously with the words.

In addition to these venerable Melodies, we possess innumerable settings of all the Sequences now in use, by the great Masters of the Polyphonic School; and many, by the Classical Composers of the 18th and 19th centuries. For these see Lauda Sion; Veni Sancte Spiritus; Victimæ Paschali; Stabat Mater; and Dies Iræ (App.).
  1. Thesaurus Hymnologicus, Tom. II. (Lipsic, 1855).