It's a birthday. It's for a birthday. For a February baby. Who likes monsters. No more questions! Also, my mistake, they are kidneys. Muscle anatomy was my strong point, what can I say. My videos are intended to be watched at 50-70 percent volume, at least on my computer.
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