How to stop sound from playing everytime we go to 1st frame ?*

Hi everyone, my app has 3 frames and a sound playing on background so everytime i go to 1st frame the music play's over himself,

is easy to get 5 instances of the music playing at same time.

How to stop this behavior ?

Music file imported to library.

Sound Linkage: export for actionScript

Sound Linkage: export in frame 1

Any help are welcome

Flash CS6 - AIR 3.4 Android and iOS > CODE:

//sound

var bgSound:BGLoop = new BGLoop();

var channel:SoundChannel=new SoundChannel();

playMusic();

//making mute;

soundBtn.addEventListener(MouseEvent.MOUSE_UP , mute);

function mute(event:MouseEvent) {

    //removing mute function then adding unmute function to same button

    soundBtn.removeEventListener(MouseEvent.MOUSE_UP , mute);

    soundBtn.addEventListener(MouseEvent.MOUSE_UP , unMute);

    //making symbol to visible;

    soundBtn.gotoAndStop(2);

    //set the volume false;

    SoundMixer.soundTransform = new SoundTransform(0);

}

//making unmute

function unMute(event:MouseEvent) {

    soundBtn.removeEventListener(MouseEvent.MOUSE_UP , unMute);

    soundBtn.addEventListener(MouseEvent.MOUSE_UP , mute);

    soundBtn.gotoAndStop(1);

    //set the volume true;

    SoundMixer.soundTransform = new SoundTransform(1);

}

function playMusic():void {

    channel = bgSound.play();

    channel.addEventListener(Event.SOUND_COMPLETE, loopMusic);

}

function loopMusic(e:Event):void {

    if (channel != null) {

        channel.removeEventListener(Event.SOUND_COMPLETE, loopMusic);

        playMusic();

    }

}