Hello :D
I don't know if there's already a tutorial of this somewhere but some of you may know this Youtube Player tutorial already:
I think I discovered the simplified version of this which works for non-premium users too!
Try pasting this in your Custom Box, Newest Deviations or Deviantart ID:
<da:embed id="VIDEO_ID" profile="youtube" width="500" height="25">
Or copy and paste this working example on your profile:
<da:embed id="UvfKkBkcBXs" profile="youtube" width="500" height="25">
Place the Youtube video ID in the "VIDEO_ID" to add your own music to your custom box.
You can also change the length of the player by chang