I am playing a lot more with a group that favors a more swinging style than traditional bluegrass. The basic feel of this music-at least to my ears-is very similar to big band swing from the 30s and 40s. Exactly what makes music "swing" music? Is it the chord structure or something else? I feel a little like the supreme court justice who said he couldn't define pornography but he knew it when he saw it--I can't really define swing but I know it when I hear it.