German composer. He entered the Leipzig Thomasschule in 1730, coming into contact there with J. S. Bach. Studied composition and keyboard with W. F. Bach; left for Hamburg in 1733 and studied theater music under Telemann, Mattheson, and Keiser. He moved to Berlin in 1739, studying with Quantz and Graun, and in 1745 became (along with C. P. E. Bach) court harpsichordist; he left the royal establishment in 1756. Nichelmann is best known for his keyboard works, especially his sonatas (1745-74) and concertos (1740-59).