This is the Google hangout hosted by 21st Century Man, based on Joseph Martelli who burned the Gay Pride Flag. If you can get past some of the immaturity, time wasted and Josephs horrible use of English, this is actually a very brilliant hangout.
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app