Here is just a little short video of finding a marble while out for a walk. To the best of my limited marble knowledge, this style of marble is called a "cat's eye". This video is meant just as a "fill video" to to help span the gaps between longer videos. The music is called "Night Music" and is in the YouTube music library for content creators.
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