like an ordinary sonata in form, but is of unusually
large dimensions.

159. _Program music_ is instrumental music which is supposed to convey
to the listener an image or a succession of images that will arouse in
him certain emotions which have been previously aroused in the
composer's mind by some scene, event, or idea. The clue to the general
idea is usually given at the beginning of the music in the form of a
poem or a short description of the thing in the mind of the composer,
but there are many examples in which there is no clue whatsoever except
the title of the composition.

_Program music_ represents a mean between _pure music_ (cf.
the piano sonata or the string quartet) on the one hand, and
_descriptive music_ (in which actual imitations of bird-calls,
whistles, the blowing of the wind, the galloping of horses,
the rolling of thunder, etc., occur), on the other. Most
program music is written for the orchestra, examples being
Liszt's "The Preludes," Strauss' "Till Eulenspiegel," etc.

160. A _symphonic poem_ (or _tone poem_) is an orchestral composition of
large dimensions (resembling the symphony in size), usually embodying
the program idea. It has no prescribed form and seems indeed to be often
characterized by an almost total lack of design, but there are also
examples of symphonic poems in which the same theme runs throughout the
entire composition, being adapted at the various points at which it
occurs to the particular moods expressed by the _program_ at those
points.

The _symphonic poem_ was invented by Liszt (1811-1886) and has
since been used extensively by Strauss, Saint-Saens and
others. It came into existence as a part of the general
movement which has caused the fugue and the sonata
successively to go out of fashion, viz., the tendency to
invent forms which would not hamper the composer in any way,
but would leave him absolutely free to express his ideas in
his own individual way.

CHAPTER XVI

TERMS RELATING TO VOCAL MUSIC

161. An _anthem_ is a sacred choral composition, usually based on
Biblical or liturgical[34] words. It may or may not have an instrumental
accompaniment, and is usually written in four parts, but may have five,
six, eight, or more.

[Footnote 34: A _liturgy_ is a prescribed form or method of conducting a
religious service, and the parts sung in such a service (as _e.g._, the
holy co