Come hang out with me while I (finally) do a little painting over the scratched up double doors leading to my bathroom. It only took me a year to get around to it! Sorry this is so short, but it really was a quick little project.
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