Getting back to music - I remember at a workshop somewhere and this Irish musician was talking about Hungarian music. He said that he just couldn't get his head round it at all, until he tried learning the dances, and then it became straightforward and meaningful.

The relevance of that is that the dancing gave the music a physical context, the equivalent of a theory, but not in a formal theoretical way. Informal shouldn't imply lack of structure. When you learn a tune by playing it with other people - a couple of notes here, and a couple more the next time it comes around and so forth - there's as much structure there as if you were learning it from a written page, but you are using different aspects of your mind.