135. The material found in the following sections is an attempt to explain in simple language certain terms relating to _forms_ and _styles_ which are in common use; in many cases the definition is too meagre to give anything but a very general idea, but it is hoped that the student will at least be set to thinking and that he will eventually be led to a more detailed and scholarly study of the subject. (The article "Form" and the separate articles under each term here defined, as found in Grove's Dictionary, are especially recommended. For examples of the various forms described, see also Mason and Surette--"The Appreciation of Music," Supplementary Volume.)
136. In a very general way there may be said to be _two styles of musical composition_, the monophonic (or homophonic)--the one-voiced--and the polyphonic--the many voiced. The polyphonic[32] style antedates the monophonic historically.
[Footnote 32: Polyphonic music flourished from 1000 A.D. to about 1750 A.D., the culmination of the polyphonic period being reached in the music of Johann Sebastian Bach (1685-1750). Haydn, Mozart, Beethoven, and the later writers have used the monophonic style more than the polyphonic, although a combination of the two is often found, as _e.g._, in the later works of Beethoven.]
137. In _monophonic music_ there is one voice which has a pronounced melody, the other voices (if present) supporting this melody as a harmonic (and often rhythmic) background. An example of this is the ordinary hymn-tune with its melody in the highest part, and with three other voices forming a "four-part harmony." The sonata, symphony, opera, modern piano piece, etc., are also largely _monophonic_, though polyphonic passages by way of contrast are often to be found.
138. In _polyphonic music_ each voice is to a certain extent melodically interesting, and the "harmony" is the result of combining several melodies in such a way as to give a pleasing effect, instead of treating a melody by adding chords as an accompaniment or support. Counterpoint, canon, round, fugue, etc., are all _polyphonic_ in style. The word _contrapuntal_ is often used synonymously with _polyphonic_.
(Sections 139 to 143 relate especially to terms describing polyphonic music.)