End background music stuttering

The background music in the End seems to stutter in an unintended way.

You can hear what I mean in this video, it lasts from about 3:55 to 3:59: https://youtu.be/gT93wNKZ1w8?t=3m52s (listen to the noises behind the commentary)

It's not just a glitch with that video. I heard the sound while making the recording and at a number of other times.