Jean-Marie Leclair was the most famous French violinist of the early part of the eighteenth century and the outstanding composer of concertos and sonatas for the instrument during his lifetime. His early training, however, was not as a violinist, but as a dancer. It was in this capacity that he went to Turin in 1722 as ballet master, a stay during which he was encouraged as a violinist by the Italian virtuoso Giovanni Battista Somis. The contact had a crucial effect on the development of Leclair's compositional style, which combines an innate French sense of elegance with fiery Italianate virtuosity in unique fashion.
The 12 sonatas of Op. 9 were the last of his four sets of solo sonatas to be issued by Leclair during his lifetime (a fifth appeared posthumously in 1767). As such, it may be seen as summation of his sonata style. It includes both extremely demanding works, such as the Sonata No. 9 in E flat, and easier pieces, such as No. 7 in G, that eschew the arsenal of virtuoso trickery developed by Leclair (this last work was written with the flute in mind; it is marked "Qui peut se jouer sur la Flûte Allemande"). The former, in Leclair's favored four-movement form, opens with a movement marked Corente a la Francese and manages to combine the composer's characteristic elegance with strong rhythmic momentum. In the final movement, Leclair pulls out all the stops in a display of virtuosity that includes multiple double-stopping (a device he was famed for playing in perfect tune), very high sequential figuration, and long slurs, an Italian technique hardly employed in French music.