Music is usually seen as one of the most expressive arts. Ask most western people about it and they'll say that it expresses emotions and related things. What generally impresses people about musical performance is their expressive ability, although the ability to perform brilliantly is also a factor. Of course, without some level of instrumental competency, little or no expression is really possible (or is it? What about improvisation?).
In general, musics that seem to rely on order rather than pure expression are seen as intellectual and cerebral, even academic rather than expressive.