It seems that the ninth is a limit. He who wants to go beyond it must pass away. It seems as if something might be imparted to us in the Tenth which we ought not yet to know, for which we are not ready. Those who have written a Ninth stood too close to the hereafter.
-on explaining the "Curse of the Ninth", a common belief after Beethoven's death where all composers will die following their ninth symphony before writing a tenth.