Some people say that knitting helps them think: keeping the hands busy leaves the mind free to wander. I've been doing the same thing -- but by playing Bach's second partita on the violin. I know that some classical musicians are wincing at the notion, but blasting through the piece without care has really helped me!
When I began [STRIKEOUT:practicing] playing violin regularly last Dec, I made a conscious decision not to be picky. In the past, my violin playing kind-of trailed away after a week or two. This time, I wanted to keep on playing for months. And more than anything else, I wanted to feel natural playing the violin.
I think I've reached that stage. I can play the first four movements of the partita completely on automatic pilot (with the exception of remembering whether I"ve played a section once or twice... I don't think I've been repeating things the right number of times). By "automatic pilot", I don't just mean "memorized" (that's a trivial task) -- I mean "my conscious thoughts are entirely devoted to planning programming exercises for my course, planning research activies, or thinking about pretty girls". Some part of my brain controls my fingers and arms, another part knows how the music is supposed to go; the two combine and do their task with the same amount of conscious thought that I apply to walking.
"Unthinkingly" playing music is nothing new for me; I did it quite often on the cello when I was a kid. I don't think I started to break myself of the habit until my early 20s. I can't remember ever doing it on the viola. Oh, my mind definitely wandered from time to time, but I never romped through half a Bach unaccompanie sonata without noticing that I'd finished a movement and started the next one.
If it sounds like I'm bragging... well, yes and no. I mean, yes, it's an impressive feat of memory and mind activity. It indicates a high level of familiarity and comfort with the instrument. It means that I can concentrate on lots of other people's activities in ensembles -- I'm very good at playing in amateur chamber music groups, since I can track everybody's parts and pinpoint where problems occur. In orchestras, I make a game out of this activity: can I recognize a problem before the conductor does (or at least, before they say anything)? If I know the conductor, can I predict what they're about to say? (for two conductors, my prediction accuracy was over 50%)
But there is a downside. Not thinking about the sound you're producing means that you won't be producing the best possible sound. Now, in the context of an amateur orchestra, that's not a terrible thing. But in the context of serious music-making (especially in a small ensemble or solo), this is a terrible thing. If you want to take music seriously, and if you want to be taken as a serious musician, then playing on automatic pilot is one of the worst possible things you can do.
However, I'm not a serious violinist. I know that I could improve much faster if I carefully analyzed myself as I played. After years of "breaking the habit", I'd never play cello without such self-analysis. And I always stress the benefits of self-analysis when teaching music.
I've decided, after careful thought and self-analysis, that the best thing for me is to play violin unthinkingly. Because playing unthinkingly is still better than not playing at all.
Besides, playing on automatic pilot gives me great thinking time. It keeps the hands busy while leaving the mind free to wander. As a highly self-critical teacher and researcher, a wandering mind is the most important thing in my life. If my hobby can support my research, they both win!