AudioScrub (PLAY Edition) funktioniert nicht

It can control the Music app (including streaming Apple Music songs), loop parts of a song, display a waveform, and rewind or fast forward like a tape player.  Use your ears to learn jazz solos, fiddle tunes, math rock, indigenous music, classical pieces, Lady Gaga… Whatever grooves you, this app will help you develop your listening ability.  Use PLAY Edition to work with playlists or streaming Apple Music songs.  AudioScrub (PLAY Edition) is a musical assistant that helps you learn to play your favourite songs.  "allows me to spend the least amount of time touching my iPad and the most time actually picking up notes and wrtiting them down on my sheet. "Very easy to use.  A fluid, scrollable waveform allows you to quickly and visually access different areas of the song.  Say goodbye to accidentally pressing the 'rewind' button and losing your place in the song.  Use REMIX Edition to change the speed, key, or tuning of the song; it has high quality sound adjustments.  You probably want to go back 'just a bit', so that's what the rewind button does: tap to jump back two seconds; hold to seek backwards.  To save time, you can set a loop to the correct number of bars and then just shift to the left or right.  I play bass and just learned a song with this app.  It's like a remote control for the Music app, so you can start playing there and finish here!  You can play, pause, and rewind without looking at the screen.  You can finally see all of the musical metadata without truncation, including the title, artist, album, composer, and release date.  AudioScrub comes in two flavours - REMIX and PLAY.  This lets you practice in musical sections without re-creating the same loop several times.