The letter A is almost always used for a point close to the beginning, but not for the very beginning itself because it is much easier to say "from the beginning". Likewise, rehearsal letters are not necessary at changes in tempo, key signature or time signature, as the name of the new tempo or signature can serve the same purpose. For example, in some editions of Beethoven's Ninth Symphony, letter A of the Finale does not occur until bar 140, when the relatively late entry of the first violins with the "Ode to Joy" theme might not stand out enough to the other players to be a convenient point of reference, whereas the reminiscences of the previous movements' themes are more easily referenced by their tempo markings.