Set it to true if you want it to repeat endlessly, but I don't recommend that. People will soon grow tired of the same song over and over. Once is enough. Change it to true if you want to hide the control panel. I do not recommend hiding the control panel in most cases.
Many people surf with their own listening preference playing.
Your sound file will play through their speakers at the same time their preference is playing, and that's annoying. Others surf from work and don't want to be found out by music coming from their computer. If they can't turn off the sound they will leave your site. One last thing, put the code at the bottom of your page. If it's at the top your visitor has nothing to do while it downloads.