Only in such comparatively simple examples as those just cited is found this perfect balance in the length of the two parts. We often observe extended sentences in the first part; and it became the custom for the second part to be considerably lengthened, to include modulations into more remote keys and even to display certain developments of the main material. For a striking example of a movement which, although definitely in Two-part form, (i.e., it is in two clear divisions and has but one theme) is yet of considerable scope and variety, see the Allegretto of Beethoven's Fourth Sonata. It was, in fact, this instinct for contrasting variety in the second part[66] which (as can be shown from historical examples)[67] gradually led to the developing and establishment of the Three-part form.
The essentials of this structure, so frequent in all pianoforte literature, are the existence of three distinct parts—hence the name: a clause of assertion in the home-key; a second clause, affording a genuine contrast to the first part in regard to key, melodic outline and general treatment, and a third clause of reassertion, which shall repeat—either literally or in varied form—the material of part one.[68] In the Three-part form, as employed in the classic Minuet and Scherzo, each of the three parts taken by itself is in complete Two-part form; and as the third part was generally a literal repetition of part one, it was not written out, but at the end of the middle part (called the Trio, because it was originally written in three-voiced harmony) we find the direction "Minuet or Scherzo da capo," meaning a return to the first part. A coda or tail-piece is often added to round out the form. As the student will become thoroughly familiar with the Three-part form, in connection with the classic Symphonies soon to be studied (each Minuet, Scherzo or Trio being an example), our illustrations show the use of this form in independent pieces and are chiefly taken from modern literature; the object being so to interest the student in the beauty of these compositions as to convince him that in all good music content and design go hand is hand. For examples[69] see Supplement Nos. 25, 26, 27.
CHAPTER VI
THE CLASSICAL AND THE MODERN SUITE
NO sooner had the Two-and Three-part forms become accepted as definite means of instrumental expression, than composers were eager to try their skill in combining dance-movements in such forms into larger groups. These compositions—known in France as Ordres, in Germany as Suites and Partitas and in England as Lessons—though all the movements were in the same key, yet showed considerable variety by reason of the contrast in the dance rhythms. They were, moreover, simple, direct and easily understood of the people.[70] This development was furthered by the perfecting of two groups of instruments: The violins, by the great Italian masters; and those precursors of our modern pianoforte, the harpsichord, clavichord and spinet. We find, consequently, the Italians—of whom Corelli was most prominent—combining these dances into groups called Sonate da Ballo: and the French composers Couperin and Rameau, developing the possibilities of keyed stringed instruments in graceful pieces to which fantastic titles, such as La Poule, Le Rappel des Oiseaux, etc., were often given. The greatest master of instrumental style in these early days was the Italian, Domenico Scarlatti (1685-1757). He was famous both as composer and performer—the first, in fact, of the long line of key-board virtuosi—and in his compositions in dance form and in those of a more abstract type there is a sparkling fancy and an adjustment of the thought to his instrument, which will keep them forever immortal.[71]
The grouping together of dance forms reached its highest development through the genius of Sebastian Bach in the so-called French and English Suites.[72] In these compositions—in the Partitas and in the orchestral Suite in D major, which contains the well-known Aria, often played in transcription for Violin solo—the dance-forms are not employed literally but are made a vehicle for the expression of varied types of human emotion and sentiment. Nor should we overlook the twelve Harpsichord Lessons of Handel—especially the superb Fugue in E minor in the Fourth Suite—which are noteworthy for their vigor, though, in freshness and delicacy of invention, not to be compared with Bach's.
We now give a tabulated list of the customary dance forms, both as found in the Classic and the modern Suite or used as independent pieces; and we shall then analyze those which have the most characteristic rhythmic pattern.