answer: #Person1# suspects Jack cancels the song. Jack denies it.
documents: #Person1#: Hey! What happened?! My song was only half way through and it skipped to the next song.
  #Person2#: I don't know what happened!
  #Person1#: You cancelled the song, didn't you, Jack?
  #Person2#: No, I didn't. Really!
  #Person1#: Then, is the machine broken or...