In 1753 Philip Emanuel published at his own expense his “Essay on the true Method of playing the Clavier.” This was the most copious work on clavier technique that had yet appeared. It was at the same time the sufficient apology for the technique of the thumb, which has become the ground-work of our fingering. When the extreme importance of the thumb had at last been recognised, it was not hard to investigate systematically the places of its application. The main rules were necessarily that, in ascending, the thumb of the right hand is put _after_ one or more black keys, and the thumb of the left hand in descending, and _vice versa_. The setting of the thumb on the black keys themselves must be avoided, and the passing over of one finger by another, which earlier had been the main feature in scale passages, was now abandoned. The whole art was built on the thumb, which passed under in the right place. This work of Philip Emanuel, which gives special attention to the legato, may be called a panegyric on the thumb. In this clear insight, as well as in the arrangement of his exercises, which begin with scales and chords, preferring the unison practice of the two hands, and advancing slowly to easy pieces, his work is still one of our most modern exercise-books. We might guess that in this diligent application of his thumb-technique to scales and broken chords, Philip Emanuel places in the forefront of his exercises certain scale figures which to-day could not correspond to the most pressing necessities of the piano-player. We should expect them to be a mere training of the hand, and no preparation for the real difficulties which appear in actual literature. A glance at the works of any great master will show us, however, that such is not the case. These very scales, chain-passages, and broken chords, which are the material of teaching, are also the figures of free composition. Some fashionable composers may have employed them extravagantly, because they were at the fingers’ ends of the players, but the most independent writers must use them, because they are, from the very nature of the clavier, the most fruitful in effect and most harmonious in sound. The old disruption of musical material into short passages of four or five notes was now antiquated. Performers practised the whole scale and the chord. And since Philip Emanuel carried through this natural training with methodical clearness, his teaching has been fruitful, and has not run merely _alongside_ of the literature. In his book we can clearly see how the clavier has contributed not least to the formation of modern secular musical perception. In this its equal temperament, which was so urgently necessary, and its complete presentation of the tone-material, which so to speak we have only to read off, have largely aided.