As told by an Inflight Crewmember:
A few months ago I was working a flight from Phoenix to JFK. A Customer boarded with a dog that was deemed to be for emotional support. Shortly after takeoff, the Customer purchased a headset. It wasn’t for her, it was for her dog!
The dog was listening to the XM Radio for a good portion of the flight. I asked the Customer if she would like her own headset (compliments of me) so that she could also listen to the radio or watch TV as the seat next to her was open. She said “no,” that her dog just wanted to relax and enjoy the music.
Not wanting to embarrass her, I discretely looked over her shoulder to see which selection the dog was listening to. I was a little surprised to discover that the dog was relaxing to U2’s “Angel of Harlem.”