Adding sound loop across scenes

I want to add a simple sound loop (only 300kb) to play across 3 scenes, that starts automatically and i need it to have a simple on/off button, how would i go about this? Should i load it from an external .swf? also if its going to not load instantaneously i would need some sort of preloader aswell.
Does anyone know how to achieve this?

Erik :cool:

i favor loading an external swf with a global sound object

Code:

---

//  in sound.fla -
_global.sndtrack = new Sound(this);
sndtrack.attachSound("thesound");
sndtrack.stop();

---

Code:

---

// in main.fla -
someMC.loadMovie("sound.swf");
// or load to level
//  loadMovieNum("sound.swf",1);
vol = 50;

this.onEnterFrame = function(){
if(sndtrack.duration > 0){
sndtrack.setVolume(vol);
sndtrack.start(0,999);
delete this.onEnterFrame;
}
};

---

hth :)