Yesterday when I was improvising on the hymns I'll be playing this Sunday, I realized I had overlooked something in my post on ugly pots. In that post, I compared the process of learning a new piece of music to that of writing and concluded that the fundamental difference between these two processes makes what works in the writing world--writing a lot to learn how to write better--not very helpful in the music-learning world.
I neglected one important element: learning a piece of music that's already written isn't really comparable to writing something that doesn't exist yet. The better comparison would be to compare composing to writing.
I came to this realization as I was trying out different ways to improvise the hymns. Hymns are difficult for me because I came to improvising in the simpler pop styles where knowing the basic chords and having a rhythm/groove is 90% of it, while hymns require more sophistication.
I digress. So as I tried one rhythm and discard it as too flippant, and tried the next (too rock), and the next (too monotonous), and go through the same processes with melodic patterns, accompaniment figures, I realize I'm playing a lot of things I don't want to do again, at least in these hymns. I can't worry about the physicality of those "wrong" decisions because trying out all these options is the only way I can get to what works.
And maybe that's why improvising scares me silly. Its very nature demands unpredictability.
Learning a new piece of music: take time, go slow. Writing and composing: keep doing lots to learn. Improvising: I'll have to trust that my muscles and my mind and the predetermined ideas will work together.