It seems that it is impossible to get the metadata of an MPEG-4 audio (.m4a) file in JavaFX 2.1, especially the title. Indeed, I'm adding a listener to the ObservableMap of the metadata from a Media object. For MP3 files, it seems everything is OK.
I'm attaching a simple NetBeans project with which you can reproduce the bug.
The app provides two buttons: one for playing the MP3 files, the other one for an M4A.
I'm working with JavaFX 2.1 on Mac OS X.