In macOS 10.15 Catalina, a new dedicated Music.app replaced the venerable iTunes:
What happened to iTunes?
With macOS Catalina, your iTunes media library is now available in the Apple Music app, Apple TV app, Apple Books app, and Apple Podcasts app. And Finder is where you can manage and sync content on your iPhone, iPad, and iPod touch.
In many ways Music is a re-skinned or renamed iTunes, rather than a true "new" app.
This seems to have lead to a number of "duplicate" questions being opened for the Music.app version of an existing iTunes question:
App opening when CD is inserted:
Play/Pause buttons (SuperUser questions, but imagine them here)
Are Apple Music questions duplicates of existing iTunes questions, if the interfaces and error messages and questions and answers are mostly the same?
Should the old iTunes questions be edited to modernize them for Music.app?
This may apply to questions about the other new iTunes-replacing apps such as Apple TV, Apple Books, and Apple Podcasts as well, but the iTunes and Music apps seem especially similar.