iPhone/iPad - Loop Background Music?

Question

Hi

First time doing this, hope you can help.

1. What the best way of playing background music for my iPad game? 1b. How do I do this?

2. Whats the best format of having that music file in for playback?

3. Will this this song happily play through the entire game, no interruptions when changing view?

4. How can I loop this music?

Thanks.