’Scherzando’ just about sums it up, I think, for both instruments. Crotchet at 100 is about all most players will achieve, and is fast enough: that makes the piece last just over one and a half minutes. The aim is to contrast the slightly bluesy bits with the more spiky main theme, and to have fun. Use as many extended techniques as you wish, particularly with regard to tonguing and rough breathing. the notes are a guide, not a precise instruction!