Much even most of the answer depends on your settings when you imported the tunes into Music. In Music > Preferences > Files there is an option to "Copy files to Music Media folder when adding to Library. If that was your setting then in all likelihood all of your tunes are in a single database and the solution is relatively simple...
  1. Go to Music > Preferences > Files and under Music Media folder location you will find the location of your current Music Library
  2. Then follow the instructions in this Apple Support Article on how to find duplicates in your Music Library without the need of a third party app. Be sure to use the Option Key version which will show you all of the exact duplicates in your Library and you can safely delete duplicates from there knowing there is another copy of the exact same Tune still in the Library.
  3. Once the duplicates have been eliminated you can copy the entire Music folder to another drive and then in Music > Preferences > Files change the location to that new location and you should be golden.
If that option was NOT selected when you imported your Music then those tunes can be scattered over multiple folders on multiple drives even extending to iCloud and recovery becomes more complex. One solution would be to
  1. Launch Music while holding down the Option key
  2. When prompted to select the Library select the option to create a new Library.
  3. Once the new Library has been created be sure the "Copy Files to Music Media folder" is checked.
  4. import ALL of your tunes to the new Library without regard for duplication
  5. Follow steps 1 through 3 to eliminate the exact duplicates and locate the entire Library at the location of your choice.
I do not contend this is the only solution, but it requires no third party apps, should clean up your Music collection, and definitely simplify future housekeeping.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein