choirs has had the
effect of developing the skilfulness of amateur singers in an
astonishing degree, but there is, nevertheless, a point where
weightiness of tone becomes an obstacle to finished execution. When
Mozart remodelled Handel's "Messiah" he was careful to indicate that
the florid passages ("divisions" they used to be called in England)
should be sung by the solo voices alone, but nowadays choirs of five
hundred voices attack such choruses as "For unto us a Child is Born,"
without the slightest hesitation, even if they sometimes make a
mournful mess of the "divisions."

[Sidenote: _The division of choirs._]

[Sidenote: _Five-part music._]

[Sidenote: _Eight part._]

[Sidenote: _Antiphonal music._]

[Sidenote: _Bach's "St. Matthew Passion."_]

The normal division of a mixed choir is into four parts or
voices--soprano, contralto, tenor, and bass; but composers sometimes
write for more parts, and the choir is subdivided to correspond. The
custom of writing for five, six, eight, ten, and even more voices was
more common in the Middle Ages, the palmy days of the _a capella_
(_i.e._, for the chapel, unaccompanied) style than it is now, and, as
a rule, a division into more than four voices is not needed outside of
the societies which cultivate this old music, such as the Musical Art
Society in New York, the Bach Choir in London, and the Domchor in
Berlin. In music for five parts, one of the upper voices, soprano or
tenor, is generally doubled; for six, the ordinary distribution is
into two sopranos, two contraltos, tenor, and bass. When eight voices
are reached a distinction is made according as there are to be eight
real parts (_a otto voci reali_), or two choruses of the four normal
parts each (_a otto voci in due cori reali_). In the first instance
the arrangement commonly is three sopranos, two contraltos, two
tenors, and one bass. One of the most beautiful uses of the double
choir is to produce antiphonal effects, choir answering to choir, both
occasionally uniting in the climaxes. How stirring this effect can be
made may be observed in some of Bach's compositions, especially those
in which he makes the division of the choir subserve a dramatic
purpose, as in the first chorus of "The Passion according to St.
Matthew," where the two choirs, one representing _Daughters of Zion_,
the other _Believers_, interrogate and answer each other thus:

I. "Come, ye daughters, weep for anguish;
See Him!
II. "W