I've been busily preparing for the musical I'm directing in the spring. You know, in most of my life, I'm not exactly anally fastidiously organized. In fact, more than one person has (oddly) accused me of being, well, disorganized. Scattered. Flaky, even. But when I direct, I really like being well prepared; and that very early.
I find the whole synergistic nature of theatre to be compelling, and I love the joy of improvisation that occurs during rehearsal, when actors "feel" a place to be, both emotionally and physically. I would never want to discount or inhibit that process. Rehearsal is a journey, after all, whose destination changes as the path is traversed. In the best productions, we never quite know what we'll have until we have it.
That said, I also believe in said spontaneity blossoming within a well-prepared structure....and that structure is best (and solely) provided by the director, and his vision of the playwright's intent. So I believe that I need to be monumentally prepared -- to know the show in its finest detail, to have planned out the jokes and comic business, the set changes and musical interpretations, the weekly/daily/hourly goals for the whole process long before we even begin.
Then, once we do begin, we'll still be changing and adding business like crazy, but (if it works right) the changes will enhance and improve the plan. FAR too often I've been involved in shows in which the rehearsal process IS the planning process. Often the show comes out fine when it's done that way, but I still believe it would have been better had it been done right.....or "right" as viewed from Tedworld, anyway.
And, for me, God is also in the details. I believe in choreographing each set change. I believe in elucidating each exact sound cue, each exact musical moment, every focus of every single lighting instrument. Skipping those details is often/usually acceptable within amateur theatre, but why? Why not try to be as perfect as you can be?
I don't think it's "Waiting For Guffman" to want to be perfect, do you?