Wikipedia describes dissonance as
the quality of sounds that seems "unstable" and has an aural "need" to "resolve" to a "stable" consonanceWhich basically means it hurts your ears and you want it to go away.
In the band pieces I have played, there is often dissonance written into the piece. And it sounds good if the instruments that are playing the opposing notes are in tune. But then there is just times when there is an instrument playing a wrong note. And it sticks out. So my question is why does dissonance sound good at times, when it doesn't at other times?
I think that this has something to do with the context that it is played within. For example, I played "Aquarium" from "The Carnival of the Animals" as a percussion ensemble piece. I had a vibraphone part, and it called for an alternating
F with the pedal down. And it didn't sound too bad when we played it together. But if I played alone, it sounded awful. Why is that?