Grove's dictionary of music and musicians

430 SEVERN SEYFEIED
the key that some theorists have agreed to
affiliate them. These are the minor seventh on
the supertonio with a chromatic major third,
and the minor seventh on the tonic, in which
the seventh itself is chromatic, as (j) and (g),
in relation to the key of C. These are respectively
the dominant sevenths of the Dominant
and Subdomiuant keys, so that in any sense
they lie very close to the principal key, and
can resolve into it with the greatest ease ; and
they are often taken witliout preparation as
distinct ingredients of its harmonic material
without other reference to the keys to which
they diatonically belong.
The minor seventh on the supertonio, with
a diatonic minor third, is a chord which has
much exercised theorists.
It comprises the same
notes as the chord which has been generally
known formerly and even partially now as the
Added sixth ; and it is more often met with
in the form from which that name was derived.
But in whatever position, it has long been
peculiar among discords for the variability of
its resolution, since the note which would be
the seventh if the supertonio were at the bottom
of the chord, stands still in resolution almost
as often as it moves downwards to the conveniently
contiguous leading note of the key.
For the various views entertained concerning
this chord, see Harmony and Root.
3. The chord of the Diminished seventh is
a familiar combination both to theorists and
musicians. It is in its complete form composed
of a set of minor thirds, and this as much as
anything gives it its notoriously ambiguous
character, since any of its elements can be
treated as the discordant note, with the result
of leading to a different key in each several
case. It is now commonly held to be the
inversion of a minor ninth with the root note
omitted. [See Diminished Intervals, vol. i.
p. 702.] c. H. H. p.
SEVERlir,THOMAS Henry—brother ofJoseph
Severn the painter, the intimate friend of Keats,
Leigh Hunt, etc.—was born in London, Nov. 5,
1801, and after many difficulties became manager
of Farn's music-business at 72 Lombard Street.
He was the first conductor of the City of London
Classical Harmonists, started in 1831. [See
vol. i. p. 526.] He was virtually self-taught, and
his knowledge of music was derived from study
of the scores of the great masters, and from
practice. He died at Wandsworth, April 15,
1881. Severn was the author of an opera, and
of various songs which were very popular in
their time ;
a Cantata,
'
The Spirit of the
Shell' ; two Te Deuras (Novello & Co.), etc.,
etc. G.
SEXT (Lat. Offieium (vel Oratio) ad Horam
Sextam ; Ad Sextam). The last but one of the
' Lesser Hours ' in the Roman Breviary.
The Office begins, as usual, with the Versiole
and Response, 'Deus in adjutorium.' These
are followed by a Hymn— 'Rector potens,
verax Deux'— which never changes; Verses
81-129 of the Psalm, 'Beati immaculati,' sung
in three divisions, but under a single antiphon ;
the Capitulum ' ' and Responsorium breve ' ' for
the Season ; and the Prayer (or Collect) for the
day.
In Collegiate Churches the Offices of Teroe
and Sext are usually sung immediately before
and after High Mass. The Plain-song Music for
Sext will be found in the Antiphonal. w. s. R.
SEXTET. See Sestet.
SEXTOLET (Fr. Sextolet ; Ger. Sextole ; Ital.
Sestina). A group of six notes of equal length,
played in the time of four ordinary notes of the
same species. To distinguish them from regular
notes of like form the number 6 is placed above
or below the group. The true sextolet is formed
from a triplet, by dividing each note into two,
thus giving six notes, the first of which alone
is accented ; but there is also a similar gi-oup
of six notes, far more frequently used than the
real sextolet, in which a slight accent is given
to the fomth note as well as the first. This
group, which really consists of two triplets, is
properly known as the Double Triplet, and
should be marked with the figure 3 over the
second and fifth notes, though it is frequently
marked with 6, and called a sextolet. The
difference is well shown in the following two
extracts from the Largo of Beethoven's Concerto
in C, op. 15. [See also Triplet.]
n I. .
! r a l^iiiJ (Tri#
DovMe Triplets.
SEXTUS {Pars sexta, Sexlwplvm ; Eng. The
Sixth Voice, or Part). In the Part -books of
the 15th and 16th centuries four voices only
were, as a general rule, mentioned by name,
the Cantus, Alius, Tenore, and Bassus. When
a fifth voice was needed, it was called Quintus,
or Pars Quinta, and corresponded exactly in
compass with one of the first four. When yet
another voice was added, it was called Sextus,
or Pars Sexta, and corresponded in compass
with another original voice -part. The extra
part, therefore, represented sometimes an additional
treble, sometimes an alto, sometimes a
tenor, and sometimes a bass ; and always corresponded
in compass with some other part of
equal importance with itself. w. s. r.
SEYFRIED, Ignaz Xavir, Ritter von,
born August 15, 1776, in Vienna, was originally
intended' for the law, but his talent for music
was so decided, that, encouraged by Peter