MIDI Can be automatic or optional sound. All of them sound like organ music. In other words, it will play it once cause you told it to and then it will loop it once. If you want it to play just once, leave out the loop code altogether. If you want it to play several times, enter whatever value you want for the number of loops.
Some codes ARE different for different browsers.
This is one of them. If you want to cover all bases, enter both the bground src code AND the embed src code. Of course you can change the text, the pic border size and you'll enter your own sound file name and picture file name. If you need a review, go back to the lesson on Clickable Pics . That was a wav file entered as a bground src code.