This video features just the sound of me, moving magic markers around. I've always enjoyed that clicky/clacky plastic sound. I tried using two of them, but they were way too noisy when I opened them, so I stopped after trying to open a third one and it squawked like a dying seagull.
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