John Sebastian Bach (1685-1750), whose mighty influence pervades the art of music of our day, and seems likely to increase in the future, wrote in all styles, even that of the Humorous Cantata. We need, however, here only mention his clavier music, which alone extends to four goodly-sized volumes; his compositions for clavier and strings, and flute; and, especially as belonging more particularly to chamber music, the Sonata in C major for two violins and clavier; another in G major for flute, violin, and clavier; and also that in C minor for the same instruments, from the so-called “Musical Offering,” which was written for the Emperor Frederick the Great of Prussia, on a theme given to Bach by that monarch himself. Among those more or less distinguished composers who contributed to the store of chamber music about this time, may be named Geminiani (1680-1762), Tartini (1692-1770), Giardini (1716-96), Pugnani (1731-98), and Philipp Emanuel Bach (1714-88), a son of John Sebastian. These lead up to, among others, Dittersdorf (1739-99), Boccherini (1743-1805), and Haydn (1732-1809), whose first String Quartett was published in 1755. [Sidenote: =Great Violin Makers=] It may not, however, be overlooked that the influence of the great violin makers, the families Amati, Guarneri, and Stradivari (1535-1745), contributed not a little to the advancement of chamber music, for these men were no mere artisans engaged in the manufacture of instruments from a commercial point of view. Rather were they true artists, and the product of their labours furnished both performers and composers the highest means of artistic expression. During the period in which they worked, the old viol was gradually changed into the violin, viola, and ’cello of our time, a change which has had a most important and far-reaching effect on the entire art of music. [Sidenote: =Haydn and Mozart=] [Sidenote: =Corelli and the Compass of the Violin=]