Right, so an association like this is not implausible: "fragrant mouse -> musk rat -> musk gland -> butthole"
Like any reasonable person, I googled. Apparently musk is used as a fixative in perfumes--the same role as phthalates. (Note that the phthalate that's predominantly used in scents is not considered a health risk, so stop worrying about it [1].) A fixative is an agent that pulls down the combined vapor pressure of a mixture. Consider how neat ethanol will quickly evaporate--you will smell it right away, but the ethanol in beer or wine or even vodka is not so flighty.
But the usage of the word "musk" in our language and culture implies a scent. If you google it, you'll find marketing sentences like this:
The appeal of the warm, sensual scent of musk reached its peak in the 1960s and 1970s, and it has now become an essential component in perfumery and cosmetics.
Was musk a dual-use ingredient that served as a fixative and a scent compound at the same dosage? If so, it seems hard to believe that there isn't a better scent and a better fixative, but musk was easy at a time when chemistry was primitive.
Side note: "Perfume: The Story of a Murderer" is a thriller that uses smell as a predominant part of the imagery. The book is unique.
1: The FDA and the nerds in reddit.com/r/fragrance agree on this: https://www.fda.gov/cosmetics/...