Eduard Constantin Lewy (1796-1846) and Joseph Rodolphe Lewy (1802-1881) were among the early advocates of the valved horn in a period when the valved horn was not readily accepted.
Eduard Constantin Lewy has been credited as being the horn player Beethoven had in mind when he wrote the long fourth horn solo in the Adagio of his Ninth Symphony. Recent research however has shown that, while it is possible that he did perform this part as a regular member of the Kärtnertor Theater orchestra which performed the 1824 premiere of this work, the music itself is clearly intended for performance on the natural horn, not the newly invented valved horn, which E. C. Lewy probably began using in 1826. His son Richard Lewy (1827-1883) was also a prominent early valved horn player.
Joseph Rodolphe Lewy premiered Schubert's Auf dem Strom in 1828. Later, Richard Wagner consulted J. R. Lewy before composing Lohengrin, a work which makes use of a unique technical approach to the valved horn that combines using the valves to make crook changes with natural horn technique. His most significant publications are his Douze Etudes pour le Cor Chromatique et le Cor Simple from 1850 and several solo works.
For more info, see THE HORN CALL
Vol. XI, no. 1, Vol. XXIX, no. 3, and THC Annual No. 8 (1996)