The elder brothers were the sons as well as pupils of the principal musician to the Duke of Brunswick, Ägidius Christoph Müller (1765–1841), and were all of them born in the city of Brunswick. Karl (Carl) Friedrich Müller (1797–1873) was first violin in the quartet and was also concertmaster to the Duke. Theodor Heinrich Müller (1799–1855) was the viola player. August Theodor Müller (1802–75) played the cello, and Franz Ferdinand Georg Müller (1808–55) was the second violin. They were especially educated by their father for quartet work, and were conceded to have brought the art of string quartet playing to a degree of perfection previously unknown.
