Yes, it's possible to add music to your site that will play automatically for your visitors.
Add a music video to your page using the Video element.
Put the video in a sidebar or in a column to automatically make it smaller, or place the video at the bottom of the page to have it completely out of sight.
Click on the settings (gear) icon in the gray toolbar and enable the Autoplay option.
⚠ Note: Keep the Show buttons option enabled if you want your visitors to be able to turn the music off.