I have always thought that music is a totally abstract art and any emotion or more broadly, meaning, is generated in the mind of the listener. It is not like language, which conveys information about common reality. Certain literature can be abstract, for example Joyce, but generally I believe we hear in music such emotions and associations as we create for ourselves. While it is true that a commonality of tradition exists about musical content and types, I tend to think communication, of emotion or anything else, in the absence of extra-musical knowledge, anecdote or tradition, based solely on primitive musical content, is an illusion. I know this view is unpopular, but my own bizarrely unusual reactions to music new to me have tended to confirm it over the years.
Emotion is surely a very small subset of musical meaning and is far too simple a label to describe even my own mental processes of reacting to music. In saying this, I do not refer to states perceived while actually playing, so I answer the question from a slightly different point of view to lostinidlewonder. However, when listening to improvisations, even close to the event of their generation, I am invariably affected, moved, stimulated, and see visions and the like, in ways unconnected and greatly out of proportion to anything I could have possibly experienced during playing them, at which time I am usually very neutral and cold.
So in this precise and personal sense, I think you are right, opus10no2, but of course it might not be quite what you meant.
Music is only truly emotional when it's great.
That is the only part I disagree with. I can be emotionally transported very easily and profoundly by second, third or fourth rate works of art. Granted, it probably says a lot more about me than about music, but it is true nonetheless.