Is the St. Luke Passion an early work of Bach’s or not? One should remember that in his Leipzig years, after having written the St. John and St. Matthew Passions , the composer still considered the music so remarkable that he personally copied out about half of the work for a performance in 1730 and then gave his son Carl Philipp Emanuel Bach the rest? Why else would Bach want to preserve the music if it had not been from his own pen?