The entire list of operas by Rameau numbers about thirty. That they did not preserve their popularity so long as those of Lulli is due to their deficiency upon the dramatic side, especially to the inherent inexpressiveness of the music itself. The treatment of the orchestra is clever in many places, showing a manifest improvement over that of Lulli, especially in the freedom of thematic work. He also ventures occasionally on enharmonic changes. Contemporaneous with him was that remarkable genius, Jean Jacques Rousseau (1712-1778), the father of the kindergarten idea, and of many other humanitarian and educational novelties. Rousseau's importance in the history of music is not sufficient to justify an account of his early days. With a great fondness for music, he found it extremely difficult to read by note, as he was almost entirely self-taught. This led him to devise a simpler notation, which he did about 1740, publishing an account of it in 1743. His system was substantially that of the tonic sol fa, except that he used figures in place of letters. He presented a memorial to the Academy of Sciences upon this subject in 1742, but his plan was so vigorously opposed by Rameau that nothing came of it; nevertheless the idea was afterward worked out by M. Paris, in the present century, and has proven very useful among the _Orpheonistes_. In 1752 Rameau produced his first opera "_Le Devin du Village_," a very light affair, somewhat on the order of what Germans call a Singspiel. The most remarkable piece that he produced was his comedy "_Pygmalion_" in 1775. There is no song in this opera. The only music in it is that for orchestral interludes in the intervals between the phrases of declamation.