コンセール・スピリチュエル
Mozart was recruited by the director of the "Concert Spirituel", Joseph Legros, to write some choruses, K. 297a, which were played without giving credit to Mozart. Then Mozart wrote a "Sinfonia concertante in E flat major" K. 297b, for a group of four wind players from Mannheim, which he sold to Legros without keeping a copy. Legros never had it copied for performance, and the work became considered "lost". Mozart at last enjoyed one great success at the "Concert Spirituel" as a composer with his "Symphony No. 31 in D", K. 297 ("Paris Symphony"), performed on June 18, 1778 "to unanimous acclaim".