At the beginning of the 1930s Ravel was working on two piano concertos. He completed the Piano Concerto in D major for the Left Hand first. It was commissioned by the Austrian pianist Paul Wittgenstein, who had lost his right arm during the war. Ravel was stimulated by the technical challenges of the project: "In a work of this kind, it is essential to give the impression of a texture no thinner than that of a part written for both hands." Ravel, not proficient enough to perform the work with only his left hand, demonstrated it with both hands. Wittgenstein was initially disappointed by the piece, but after long study he became fascinated by it and ranked it as a great work. In January 1932 he premiered it in Vienna to instant acclaim, and performed it in Paris with Ravel conducting the following year. The critic Henry Prunières wrote, "From the opening measures, we are plunged into a world in which Ravel has but rarely introduced us."