No one in the whole movie ever asks anyone, Did you write this letter' Part of the reason is that no one wants to hear that it isn't for them. As soon as they read it, they want it to be theirs.
But to me the actual sound of the words is all important; I feel always that the words complete the music and must never be swallowed up in it.
When I did plays in high school and college, I never remember memorizing my lines, but once I had blocking, I had all my lines memorized. Once I had movement associated with words, it was fine. Before I had blocking, it was just text on a page. Once it became embodied, it was much easier.