The "new" Music.app on iOS 5 on iPad does not support viewing of Audiobook (.m4b / .aa) chapters and their titles. Nor does it provide for direct selection of chapters. This is a loss of functionality compared with the iPod.app on iOD 4.3 on iPad. The prior app provided a means of viewing the chapters and their titles and the direct selection of a desired chapter. The current Music.app does provide for the user to tap the fast forward / backward buttons to skip to chapter marks but there is no display of the chapter title for a selection so there;s no useful way to know where one is in the Audiobook. Further, Audiobooks frequently contain 10s of chapters in a segment (usually limited to around 100 MB / segment (track if you prefer) by Audible). The iPhone (and I presume iPod Touch) version of the Music.app retains the chapter viewing and selection functionality from previous iOS 4.3. Only the iPad version of the app has lost the functionality. Without viewing of chapters and their titles and direct selection of chapters, Audiobooks in the Music.app are basically unusable.