An exceptional and prolific baroque composer, he produced works ranging from violin concertos, suites, and the six Brandenburg Concertos (1720-1) to clavier works and sacred cantatas. Large-scale choral works include The Passion according to St John (1723), The Passion according to St Matthew (1729), and the Mass in B minor (1733-8). He had twenty children: Carl Philipp Emanuel Bach (1714–88) wrote church music, keyboard sonatas, and a celebrated treatise on clavier playing, and Johann Christian Bach (1735–82) became music master to the British royal family and composed thirteen operas