...yeah, the musky one is a bit off... "musk" used to be like Nova pointed out, a specific thing secreted by specific animals... and it was used as fixative for perfumes!
But the term 'musk' has become an universal scent description pretty much all animals can produce in some way or another... They are not the same chemical composition as 'true musk', but they do basically the same thing. Even people can get musky!! (heck I think even some plants have 'musk'!)