=Equal Temperament=.—An early difficulty in the case of keyed instruments was the matter of tuning, caused by the fact that it was found scientifically impossible to tune all the intervals of the scale at the same time to the true pitch; that is, the pitch demanded by the natural overtones of the fundamental note of the scale. At the outset, for instance, it was found that if the fifths were tuned true, the octaves would be a trifle sharp; and, conversely, if the octaves were true, the fifths would be a trifle flat. In the case of stringed instruments, where the tone was made by the performer, it could be so modified as not to conflict seriously; but with keyed instruments this was impossible. Thus, many systems of tuning or “temperaments” were tried, such as having two keys for two notes nearly in unison, like F-sharp and G-flat, most of these resulting in the possibility of playing in a few nearly related keys, to the exclusion of the others. Finally, through the influence of =J. S. Bach= (1685-1750) and the Frenchman =Rameau= (1683-1764), the simple expedient was definitely adopted of tuning the octaves true, and dividing each octave into twelve equal parts, thus uniting such notes as F-sharp and G-flat in one tone slightly out of tune with either, but not enough seriously to offend the ear. This, called “_equal temperament_,” was a great gain to music, since it not only removed a radical defect in keyed instruments, but also opened the door to that free interchange of keys which has done so much toward enriching the coloring and scope of succeeding compositions. REFERENCES. Grove.—Dictionary of Music and Musicians, articles on the Clavichord, Virginal, Spinet, Harpsichord, Pianoforte. Naumann.—History of Music, Vol. I. Weitzmann.—History of the Pianoforte. Brinsmead.—History of the Pianoforte. Rimbault.—The Pianoforte: Its Origin, Progress and Construction. Spillane.—History of the American Pianoforte. QUESTIONS. What principle did the first attempts at piano-making recognize? To what circumstance are we indebted for the attempt to make an instrument of the Clavier type? What are the two classes of stringed instruments with keyboard as known in the 11th century? State the steps in the development of the Clavichord principle. Describe the Clavichord. Describe the Harpsichord principle. Describe the Virginal and Spinet. Describe the Harpsichord. Who was the inventor of the Pianoforte? When did he exhibit the first instrument? Who were the early makers? What points of superiority did the Piano have over the Clavichord and the Harpsichord? What successive improvements were made by various makers? What is meant by Equal Temperament? LESSON XXVI. THE EARLY ITALIAN CLAVIER COMPOSERS.