This is one of my Duos I have made occassionaly. It is suitable for any melodic instruments, and I play it on my Concertina, and wooden Chalumeau, in my video attempt here. A simple melody passes, or is exchanged, from one instrument to the other, and gently interracts. [It is NOT a duet or battle between parties] The two different instrumental types seem to work together in an unusual way - giving a distinctive double reedy timbre of sound quality. The more steady metallic reed of concertina contrasts with the wavering single cane reed of the Chalumeau.