Detailed biography: The Univerity of Rochester Sibley library gives Müller's dates as 1894-1950, but if the 1894 birth date is correct, then Müller wrote his Unterhaltungstücke when he was 8 years old. :-) Wikipedia in Germany lists this person, who "also" was a trombonist who wrote study material. Wikipedia (German). Probably the same person, which makes the nationality German and the dates 1849-1909.
