Who invented the system of equal temperament, no one knows. It is mentioned in the "Harmonic Universelle" of Marin Mersenne, the French writer before quoted, but it is quite certain that it was not extensively employed before the time of Bach, who brought the system to practical perfection, and demonstrated it in his "Well-Tempered Clavichord," a set of twenty-four preludes and fugues going through all the keys. The science of equal temperament was first set forth in a satisfactory manner by Jean Philippe Rameau, the French opera composer, in his "Traité de l'Harmonie," Paris, 1722.
[Chapter VIII]
The Evolution of Piano Playing
Work of the organ schools of Venice and Rome—Polyphonic playing and the advent of the singing style—Scale playing and the use of the thumb—Bach's fingering and Mozart's vocal playing—Development of tone-color—Pedalling and variety of touch—Chopin, Schumann, and Liszt technics.
THE origin of piano music, and, indeed, of much of the entire mass of modern instrumental music, was the organ compositions of the early masters. The early clavichords were used almost exclusively for the home practice of organists; and even after it became fashionable for young ladies to learn the art of playing, there was no difference whatever between the style of music written for the organ and of that composed for the clavichord, nor in the manner of playing either instrument. Every musician knows that in our time the kind of touch used for the organ is essentially different from that used for the piano, and that music suitable for one instrument is not suitable for the other. But it was not thus in the earliest days; for the only professional pianists (or clavichordists, to be more precise) were the organists, and instrumental music had not yet reached a state of development high enough to produce a divergence of styles. The fact that the same keyboard was used in both instruments was sufficient to suggest to the early organists that one style of playing was practicable for both. It naturally did not occur to them to write different sorts of music; and it is necessary, therefore, for us to inquire what was the nature of the early organ music.
We have already seen that when the organ was first introduced into the church it was employed simply to play the same notes as the voices sang. This practice naturally suggested to composers a style for their organ music when they began to write for the organ independently of the voices. Just when they began to do that it is not possible to say, because the early compositions have not been preserved as the great masterpieces of church counterpoint have. The first organist of repute whose name has come down to us was Francesco Landini, of Venice. He flourished about 1364. But we do not meet with any definite school of organists in Venice until the third period of the Netherlands school, when the great Adrian Willaert was the leading master. In 1547 was published a collection of music entitled "Ricercari da cantare e sonare," by Jacob Buus. These "ricercari" were compositions in the old ecclesiastical keys and the polyphonic style. "Da cantare e sonare" means that they were to be sung or played. Anything "cantata" was vocal, anything "sonata" was instrumental; and so after a time they began to call a composition for instruments alone a sonata, though it was a very different sort of work from a sonata by Mozart. In 1549 fantasies for three voices, vocal or instrumental, by Willaert were printed. Willaert used original themes in his fantasies, and his style shows a gradual approach to the modern manner. In 1551 was issued a collection by various authors, entitled "A New Collection of Various Kinds of Dances to be Played on the Harpsichord, Clavicimbal, Spinet, or Monochord." The word "dances" is very significant, because it shows the first recorded effort to write instrumental music in purely instrumental form. In this collection there was no polyphony, but the melody of the dance was in the treble, and the bass was a simple chord accompaniment. This is an evidence of the manner in which the music of the people began at that early date to influence compositions for instruments.
But the dominion of church counterpoint was not to be overthrown at once; and so we find that the first clearly defined instrumental form was the "toccata." Those of Claudio Merulo, a Venetian organist, printed in 1598, were the first to be published. They were written for the organ, and resembled Willaert's church vocal music in that they consisted of running or polyphonic passages, followed by successions of broad chords. Giovanni Gabrieli did more, perhaps, than any other of the Venetians to lead instrumental music toward the modern style. He wrote what he called "canzone;" and in these compositions the melody assumed a position of importance. Furthermore, he showed a tendency to make his melodic themes recur at regular intervals, although he had no well-defined system. Still, he made important advances. The Roman school of organists made valuable contributions to the development of instrumental music. Girolamo Frescobaldi (1591-1640) wrote ricercari in which there was something like a systematic employment of clear melodic themes. He wrote canzone in which there were passages slightly resembling the choral hymns of the Reformation; and in his "Capriccio Chromatico" he made a bold use of chromatic harmonies. Indeed, his music shows a general tendency toward the modern major and minor keys. We are not surprised, then, to find in the works of Bernardo Pasquine (1637-1710) arpeggios (running passages composed of the notes of chords, much used in modern piano music), flowing passages for both hands, and repetitions of the thematic ideas. But the manner of composing for the clavichord and harpsichord had been so greatly influenced at this time by the evolution of a distinct method of playing the instruments that we must, before advancing any further, go back and briefly review that topic.
The first systematic method of playing the organ and harpsichord was set forth in 1593 in a book by Girolamo di Ruta, a Venetian, and it contained rules for fingering which were in use for more than a century. A work by Lorenzo Penna, published at Bologna in 1656, shows very clearly what the general principles of clavichord and harpsichord technic were in that day. "In ascending the fingers of the right hand move one after the other,—first the middle, then the ring finger, again the middle, and so on in alternation. Care must be taken that the fingers do not strike against one another. In descending, the middle, followed by the index finger, is used. The left hand simply reverses this process. The rule for the position of the hands is that they shall never lie lower than the fingers, but shall be held high, with the fingers stretched out." This style of fingering held its own until Bach's time. It was in existence as late as 1741, though more fingers were employed. But the fingers were still held straight, and the thumb was not used.