(also off-topic)
I inquire because I would actually like to do the same – newer versions of the Music app are a usability and visual downgrade. Album view, for example, only shows six fixed-dimension covers, no matter how wide your screen is. Clicking on an album takes you to another screen – annoying! I just want to see the tracklist.
I have a 2018 Macbook that's still running Mojave because I vastly prefer the UI overall. I pray for a UI refresh/patch every WWDC but Apple doesn't really seem to be taking it seriously. Sonoma is an improvement, but there are still so many inconsistent or unpolished areas of the post-Catalina interface style. The cyan-blue folders are still awful; filename selection highlights in Finder aren't centered; the taskbars have become comically large. Small details, but embarrassing for a company of such design pedigree.