Korean pianist Sonya Bach studied with Lazar Berman and Alicia de Larrocha, and is a Steinway artist. For such a great virtuoso of both harpsichord and organ, it is remarkable that J.S Bach composed only one original work for keyboard and orchestra: the 5th Brandenburg Concerto which with its huge 65 bar cadenza in the first movement created the blue print for all piano concertos that followed. However, Bach, the great arranger, turned to his other concertos and created 7 (No.6 omitted here is for keyboard, 2 flutes and strings) concertos that give us an idea of his ability as a player, but also his genius in transcription, often taking great liberties with the original material to create new concertos. Bach performed these concertos at social gatherings of the Collegium Musicum in Leipzig, and he directed from the keyboard.