Apple Music has become increasingly hostile to user local audio files. What I mean is audio files you create and want to store in Apple Music. Even the interface to manually manage songs is grayed out and doesn’t show you your files that are stored locally in the Finder. In addition, unrealBook only supports locally stored audio files in the iTunes/iPad/iPod library. It always only supported local files, but at some point Apple did or did not support linked cloud files. On iOS12 it certainly doesn’t. On iOS15 it seems like it actually does supported cloud based songs.
For this reason, (years ago) I implemented direct linking of supported audio files (mp3, mp4, wav, aif etc) in the unrealBook documents folder. It’s easy to use. Simply Airdrop, dropbox, open in…. any audio file to unrealBook and it will be imported. After that, use the CD Menu->Music Controller ->link audio file button or CD->menu->play audio file->then + button or create a transmogrify play button and use the use file button to link the audio file.
This is way more reliable, has none of the problems of linked Apple Music and is not subject to any iOS changes to Apple Music.
In short, don’t use Apple Music for linked audio files in unrealBook if you can.
Choose Play iTunes Song access your iTunes Music Library.
Choose between your Playlists, Artists, Albums or Songs. Select a song to play by pressing it. The song should start playing.
Press the Back button on the top left to go back to the Music Controller.
Press the link icon in the Music Controller to link the currently playing song to the PDF. Note that you can link a different song to each page of a PDF. Every song that you link should have a name and artist defined in iTunes.
Press the Music Button to access the Music Player controller to control playback and link a song in your iTunes library to a PDF file.
The Music Controller will control the playback of any songs linked to the current PDF. The -4 and +4 buttons will allow you to skip forward and backwards by 4 seconds. The slider will allow you to jump to any point of the song. The Start offset will allow you to start from a predetermined point from the beginning in seconds.