Restoring a music playlist from a Time Machine backup.

1. With Music closed rename the package ~/Music/Music/Music Library.musiclibrary as Music Library (Temp).musiclibrary.
2. Restore the package ~/Music/Music/Music Library.musiclibrary from Time Machine from a date before you deleted the list.
3. Open Music. Select the list and use File > Library > Export Playlist... Export as an XML file.
4. Close Music. Rename Music Library.musiclibrary as Music Library (Old).musiclibrary.
5. Rename Music Library (Temp).musiclibrary as Music Library.musiclibrary. Launch Music.
6. Use File > Library > Import Playlist... and import the exported list.

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Make sure Music is closed. Open Finder. Open your user's Music folder. Open the Music folder inside that. Now enter Time Machine by clicking the icon in the status area at the top of the screen. See Restore items backed up with Time Machine on Mac - Apple Support. Pick a suitable date, select the Music Library(.musiclibrary) file and click Restore. There is no point in overwriting all the unchanged media files. Deleting a playlist from the library doesn't delete any songs from it so those should have remained in place. The playlists are inside the file that you restore. Once this is done launch Music, the library should now be in the state it was in when it was backed up complete with the playlist that you removed in error.

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OK, so your active media folder is /Users/jazzman/Music/iTunes (original)/iTunes Music/ which although unconventional shouldn't affect the process of restoring the database from Time Machine. Follow the steps as I gave them here.

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Playlists are stored in the library database. See Use multiple libraries in Music on Mac - Apple Support. You're going to be using the choose library process to ensure that Music opens the file you restore from Time Machine rather than some cache of the library it may make in another location.

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~ is your user's profile folder. Your Music library is normally in the path mentioned in 1. above, i.e. the Music folder in the Music folder in your profile folder. The file Music Library.musiclibrary (which may appear without the extension) is actually a folder containing multiple files made to appear as a single file, i.e. it is a package. This contains the Music library database, which in turn contains all of your playlists. The aim of the steps above is to temporarily restore a recent version of this database, export the playlist as an XML file, restore your current database, then import the exported list.

A playlist is an ordered list of references to tracks in your library. Because they don't normally exist anywhere as individual files you need to temporarily restore an older version of your library database to recover the missing list.

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Quite possibly. The library itself may not be that large. Is there a Media folder as well as the Music Libray(.musiclibrary) file? If not your active media folder is likely to be ~/Music/iTunes/iTunes Media, a legacy from iTunes on an earlier version the operating system.

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The User's Music folder is /Users/jazzman/Music/

Your Music library folder is /Users/jazzman/Music/Music

Your active Music library database is /Users/jazzman/Music/Music Library(.musiclibrary)

You can check to see if the last modified date of this last thing changes when you open and close Music. If so then this is the file that needs to be replaced with an earlier version from Time Machine. If not then perhaps you've created another .musiclibrary database somewhere along the way. You would need to find that file, and restore an older version of that file instead.

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You've mentioned that you don't have an Apple Music subscription, but do you have a subscription to iTunes Match? Assuming not try holding down Option as you launch Music, click the Choose Library button, then explicitly choose the library file ~/Music/Music/Music Library.

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