J. S. Bach arranged many concertos by various composers probably at the request of Prince Johann Ernst of Saxe-Weimar. Among them are timeless favorites by Vivaldi and others, all in keyboard arrangements noteworthy for their moderate difficulty, fullness of sound and lively execution. Here, for the first time, these works are presented on the basis of all available sources, edited in accordance with the guidelines of the ground-breaking New Bach Edition. The result is an exemplary publication that meets all the demands of historical performance practice.