Part 13 (2/2)

[Ill.u.s.tration: BEETHOVEN]

The _small three-part primary form_ is like the two-part primary form except that it has a section of contrasting material interpolated between the two periods. This middle part is usually an eight-measure phrase.

The _large two- and three-part primary forms_ usually have sixteen-measure periods instead of eight-measure ones, but are otherwise similar in construction.

These various _primary forms_ are used in constructing many varieties of compositions, among them the _theme and variations_, the _polka_, the _waltz_, the _march_, etc., as well as most of the shorter movements in sonatas, quartets, etc. They are used in vocal music also, but are less apt to be regular here because the form of vocal music is largely dependent upon the structure of the text.

147. A _theme_ is a fragment of melody used as the subject of a fugue, as the basis of the development section in ”sonata form,” etc. Sometimes it is a complete tune (often in period form), on which variations are made, as _e.g._, in the familiar _theme and variations_.

148. _Thematic development_ consists in taking a short theme (or several short themes) and by means of transposition, interval expansion and contraction, rhythmic augmentation and diminution, inversion, tonality changes, etc., building out of it a lengthy composition or section of a composition. Fig. 60 _b_, _c_, _d_, _e_, and _f_ show how the theme given in Fig. 60 (_a_) may be varied in a few of these ways. There are hundreds of other fas.h.i.+ons in which this same theme might be varied without destroying its ident.i.ty. For other examples of thematic development see the development section of Sonata Op. 31, No. 3, as a.n.a.lyzed in Appendix E. [Transcriber's Note: Corrected error ”Sec. 3” in original.]

[Ill.u.s.tration: Fig. 60.]

For further ill.u.s.trations of development in the case of this same theme, see--Christiani--The Principles of Expression in Pianoforte playing, p. 144, ff. from which the foregoing themes have been adapted.

149. A _rondo_ is an instrumental composition (in h.o.m.ophonic style) in which a certain theme appears several times almost always in the same form (_i.e._, not thematically varied), the repet.i.tions of this theme being separated by contrasting material.

The _rondo_ is the oldest of the larger monophonic forms and has been used in many different ways, but perhaps its most characteristic construction is as follows: (1) Princ.i.p.al subject; (2) second subject in dominant key; (3) princ.i.p.al subject; (4) third subject; (5) first subject again; (6) second subject, in _tonic key_; (7) coda (or ending).

The student should note particularly the problem of repet.i.tion and contrast (mentioned in Sec. 134) as here worked out, as the rondo was the first monophonic form in which this matter was at all satisfactorily solved, and its construction is especially interesting because it is readily seen to be one of the direct predecessors of the highest form of all--the sonata. Examples of rondos may be found in any volume of sonatas or sonatinas.

150. A _suite_ is a set of instrumental dances all in the same or in nearly related keys. The first dance is usually preceded by an introduction or prelude, and the various dances are so grouped as to secure contrast of movement--a quick dance being usually followed by a slower one.

The suite is interesting to students of the development of music as being the first form _in several movements_ to be generally adopted by composers. It retained its popularity from the beginning of the seventeenth to the end of the eighteenth centuries, being finally displaced by the sonata, whose immediate predecessor it is thus seen to be.

The _suite_ was formerly written for solo instrument only (harpsichord, clavichord, piano) but modern composers like Dvo[vr]ak, Lachner, Moszkowski, and others have written suites for full orchestra also.

151. Among the dances commonly found in suites are the following:

_Allemande_--duple or quadruple measure.

_Bolero_--triple measure.

_Bouree_--duple or quadruple measure.

_Chaconne_--triple measure.

_Courante_--a very old dance in triple measure.

_Csardas_--Hungarian dance in duple or quadruple measure.

_Gavotte_--quadruple measure.

_Gigue_ (or _jig_)--duple measure.

_Habanera_--Spanish dance in triple measure.

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