Comparison of surviving texts of eighteenth-century composers, Bach and Mozart in particular, show that considerable latitude was granted to performers for extempore embellishment and cadenzas, not only in arias and concertos but in solo works as well. Amateurs required prepared elaborations, whereas professional performers did not. The aesthetic of improvisation in performance is shot through with risk—an element sadly lacking in the training and the performance of classical music at the present time. This article finds distinct parallels among what it calls the “ghetto language” of 1730s Leipzig, 1780s Vienna, and 1930s New York. Duke Ellington is said to be Bach's and Mozart's true successor.