The start page of my website contains music, I.E. plays it, firefox doens't

I have a mp3 song linked to my startup page of my website, Internet Explorer automatically plays the music as soon as the first page of my site is loaded in the browser, unfortunately Firefox doesn't do this, what is the problem ? There is no problem playing sound (music etc.) when visiting i.e. YouTube or other sites and when a song is started after clicking a link. Do I have to add another add-on ?