[Zubersoft]

It sounds like performance mode has been enabled. To disable performance mode, tap the lock icon in the floating toolbar at the bottom right corner of the library screen. This same toggle can be accessed by tapping the bottom right corner of the screen while a song is loaded to display the quick action box. After disabling performance mode, you should be able to access the annotation editor with a three finger tap or by tapping the brush icon at the top left corner of the song overlay.

Mike