Expectations
I was talking with Vardan today during our lesson. I was saying to him that in music, I like to create expectations for the listener, through repetition or sequencing, and then disturb the listener by denying them that expectation. The feeling of surprise that overtakes the listener is simultaneously shocking and exciting.

The listener cannot possibly know ahead of time what a composition's structure will be. They rely on their first experience listening to determine how the piece develops. As they hear patterns, the brain makes expectations. Certain chords should happen here and there. The first wave of surprise at a substation or alteration forces the listener to stand guard, suspecting more surprises to come. But when? And how? The listener becomes tense with anticipation, not knowing when the next surprise will appear.

I think there is joy in that. That's what makes the music interesting. It leaves things to be desired; questions to be answered.