Recovering lost playlists

Press and hold down Alt/Option as you launch Music, click the Choose Library... button, then browse to and open your old iTunes Library.itl file, and choose a location to save the converted library.

You might want to rename the current ~/Music/Music folder so your converted library can go there as this is the default location. See also Managing your Mac media libraries - Apple Community for advice on reorganizing your content to the new layouts.

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When you option-start-Music and choose a .itl file to open the next step is to select a folder in which Music will create a new folder (e.g. Music, Music 2, etc., you can edit the name). It then saves a Music Library.musiclibrary package in this location and shows the content that has been converted. Tracks stay on their original paths, in this case your old iTunes Music folder. Music may potentially arrange files to match metadata if that hadn't been the case in the past. The standard layout is <Media Folder>[/Music]/<Artist>/<Album>/## <Name>.<Ext>, where the [/Music] is an optional additional subfolder for music items more relevant to iTunes than it is to the Music app. The user tip Managing your Mac media libraries - Apple Community goes into details.

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What did you upgrade from? See Empty/corrupt iTunes/Music library after upgrade/crash - Apple Community for general advice.

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