Yeah. The harmonica is a cool damn instrument. So simplistic, but it really adds something to a song, especially on a well-placed bridge. Unfortunately nearly gone in modern music, as far as I can tell. EDIT: ick that first post was so bitter. Gone. No excuse, really.
Tonight we used it more to effect mood, in a more chordal way, I suppose. There were no "harmonica solos." In this sense, much like a melodica or an accordion, you are able to control the volume and melody in a way that can be quite emotive. With a harmonica/melodic you have the advantage of using your actual breathe to convey your feelings. It's a powerful thing. It's easy to feel a very real and direct connection and control to what you are doing.
Example. That song signals loss and longing well before Dylan opens his mouth, all because of the instrument choice. Sometimes, though, true harmonica solos are clumsy and jarring. They don't always fit. I can't wait to hear how y'all pulled off a 'chordal' sound. Rhythm harmonica.