Monique, that's helpful, thank you, and confirms in detail what I'd imagined to be the case. Naming of early instruments is always fraught with difficulties - 3 different instruments called a gittern, for example, and the same instrument was often called different things in different places. The cornamuse/bagpipe etymological link is interesting in itself, though, as if you remove the bag and drones from a bagpipe you essentially have a coramuse; bend it and you have a crumhorn.