Müller, Iwan, German clarinetist, basset-horn player, instrument maker, and composer; b. Reval, Estonia, Dec. 14, 1786; d. Bückeburg, Feb. 4, 1854. He toured throughout Europe, and served as a chamber musician at the St. Petersburg imperial court (1800–07). He developed an 18-key basset horn (1808) and a 13-key clarinet (1809), and also claimed for himself the invention of the alto clarinet; made Paris his headquarters (1809). Although he faced the opposition of conservative instrument makers, his improved clarinet eventually won general popularity. He spent the last years of his life at Bückeburg as a court musician. He pubi, a method for his new instruments, and also composed 6 clarinet concertos and 2 clarinet quartets.
—Nicolas Slonimsky/Laura Kuhn/Dennis Mclntire