I think "understanding" music can be useful, if you're talking about cognition. Technical facility can certainly be enhanced by it, if you are a performer.

Personally I think that "understanding" should encompass an internal sensibility as well, and my definition does. This might be related to "feeling" or "soul".

Perhaps it's my eclectic backround-- listening to folk music as diverse as Hungarian/Danish/Celtic as a kid, as well as the full range of classical--including opera every Saturday on the radio-- and Lutheran church music of the liberal sort. I find myself sent into ecstacies of various sorts by everything from Beethoven's 6th (I have loved it since age 14-a very impressionable age) to Tuvan throat singing to Middle Eastern folk music. I still hate opera (well maybe hate is too strong a word) and don't care for jazz or Bach. And I still love Celtic and Old-time music and the music of my foreBears. I think what sounds good to us is as much about our character/personality as anything-- or perhaps it's really about the soul... my taste in music is much like my brother's but not much like my sister or father, who prefer Bach and Aarvo Part (sp? --he does nothing for me...)If it's all about the structure of the ear-- I guess I didn't inherit my Dad's...

Bekki