I listened to the Gordon Dando's Classic Banjo documentary a while back on Chris Sand's youtube channel and it's a real treat. Within the video at about 1:08:35 Horace Craddy plays his arrangement of Duke Ellington's Caravan. I'm having a hard time hearing Caravan in his arrangement. I know there are obviously more songs that have been interpreted into the classic style, but this is the only jazz piece that I have seen. Besides the styles of music that are clearly marked (Schottische, Waltzes, Mazurka, Polka, Marches, Patrols, Rags, etc...) what are the compositional rules of classic banjo that makes a piece fit within the medium?