treatment. The first-mentioned, which is from the Slow Movement, is further remarkable as an example of a peculiar manipulation of the device by which modern composers have obtained very impressive results. This is the change of emphasis in the successive steps of which it is composed. For instance, if the characteristic group consists of three chords of equal length, and the time in which it occurs is a square one, it is clear that the chord which is emphatic in the first step will be weakest in the next, and vice versâ. This form will be most easily understood from an outline example:—
![{ \new Staff << \override Score.TimeSignature #'stencil = ##f \time 4/4
\new Voice \relative c'' { \stemUp
\[ c4 b a \] d | c b e d | c f e d | g f e }
\new Voice \relative c' { \stemDown
c4 e f d | f g e g | a f a b | g f c } >> }](http://upload.wikimedia.org/score/a/6/a6y2w6wgyhqq1ey7uti10o527zodv3h/a6y2w6wg.png)
A passage at the beginning of the Presto at the end of Beethoven's Leonora Overture, No. 3, is a good example of a sequence of this kind in a single part. It begins in the following quotation at *
![{ \override Score.TimeSignature #'stencil = ##f \time 4/4 \relative c'' { r8 c g'^"*" f e d c b | a' g f e d c b' a |
g f e d c' b a g | f e d' c b a g f | s^"etc." } }](http://upload.wikimedia.org/score/0/2/02r1ifdx4shunh7p813bzxc4cr4zqhp/02r1ifdx.png)
The extension of the characteristic group of a sequence is almost unlimited, but it will be obvious at once that in harmonic sequences the shorter and simpler they are the more immediately they will be understood. In long-limbed sequences the hearer may soon perceive that there is a principle of order underlying what he hears, though its exact nature may always elude his apprehension, and in respect of the larger branches of form this is a decided advantage. Among short-limbed emphatic sequences in modern music, the one of eight steps which occurs towards the end of the first full portion of the Overture to the Meistersinger is conspicuous, and it has the advantage of being slightly irregular. The long-limbed sequences are sometimes elaborately concealed, so that the underlying source of order in the progression can only with difficulty be unravelled. A remarkable example of a very complicated sequence of this kind is a passage in Schumann's Fantasia in C major (op. 17), in the movement in E♭, marked 'Moderate con energia,' beginning at the 58th bar. The passage is too long to quote, but the clue to the mystery may be extracted somewhat after this manner:—
![{ \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
\time 4/4 \key ees \major \relative a {
r4 \[ a d c | bes f'2 bes,4 | b f'2 b,4 | c f d f |
ees \] \clef bass g, c bes | %end line 1
aes ees'2 aes,4 | a ees'2 a,4 | bes ees c d |
bes \clef treble d g f | ees bes'2 ees,4 | %end line 2
e bes'2 e,4 | f bes g bes | aes8 s_"etc." } }](http://upload.wikimedia.org/score/1/d/1dbk9gnygnx3atdbks8ebusoh1hxev3/1dbk9gny.png)
In order to see how this has been manipulated reference must be made to the original.
A species of sequence which is familiar in modern music is that in which a figure or melody is repeated a tone higher; this has been termed a Rosalia. [See vol. iii, p. 160.] Another, which is equally characteristic, is a repetition of a figure or passage a semitone higher; an example from the Eroica Symphony is quoted in vol. ii. p. 346 of this Dictionary.
The device has never been bound to rigid exactness, because it is easy to follow, and slight deviations seasonably introduced are often happy in effect. In fact its virtue does not consist so much in the exactness of transposition as in the intelligibility of analogous repetitions. If the musical idea is sufficiently interesting to carry the attention with it, the sequence will perform its function adequately even if it be slightly irregular both in its harmonic steps and in its melodic features; and this happens to be the case both in the example from the Slow Movement of Beethoven's Sonata in B♭, and in the passage quoted from Schumann's Fantasia. It is not so, however, with the crude harmonic successions which are more commonly met with; for they are like diagrams, and if they are not exact they are good for nothing.
[ C. H. H. P. ]
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,