“Searching for traces of once-admired Nassau court music in European and American libraries made it apparent that, despite large losses, there still survives a corpus of court music, though hard to fully assess due to its size and geographical scattering. The majority of these autographs and manuscripts are unheard pieces, condemned to two and one-half centuries of oblivion. The 350th birthday of Count Johann Ernst of Nassau-Weilburg (1664-1719) provides an appropriate occasion to let the brilliance of the Nassau court music be heard again.