Note on music autoplay:
On some browsers, audio will not play automatically, but only in response to user interaction.
So the code gives the user play and pause buttons.
See notes on Audio autoplay on web pages,
Use your own music
Get a downloadable file of some music you like.
One site with free music is
freemp3cloud.com.
There are many others.
When you find music you like, download the music file to your computer.
The background is a program, showing the JavaScript graphics used on this site.
The globes light up when you log in.
Drag the background to move the camera.
Customise background: