Bah! Now I see why that description is on the birdpipes we have in FRC.
I suppose in a fantasy setting we're allowed to change words to suit our own purposes. However, a shalm is an actual instrument, and it is not a panpipe.
It's as if we decided that, in FR, "gorget" means "armor that protects the knee" or "baldric" means "a fancy headdress". Bah! Just because a word sounds interesting doesn't mean you should use it willy-nilly.