AS3: How to access and control embedded sounds in an external swf?

Question

I rarely use sounds in AS3/Flash. I am using Flash Pro CS6, but I can't seem to figure out how to access, control (play, stop, etc) sounds embedded in an external SWF loaded into the main SWF.
It's easy to control them when embedded on the main swf. However, on an externally loaded SWR, I get all kinds of errors. For this app, I really need to embed them in the external SWF.
I read several solutions, but none seem to work.
I embed the sound an mp3 file called soundSegment1.mp3 using Flash CS6 import tool and then open the actionscript properties panel on flash to select the class name: SoundSegment1. Then I edit the class code and create a file called SoundSegment1.as and it's saved right next to my document class main.as in the same directory. The code of the SoundSegment1 class looks like this:
package  {
    import flash.media.*;
    public class SoundSegment1 extends Sound
        public function SoundSegment1 ()
            // no code in here
        public function playSound()
            var soundSegment1:Sound = new SoundSegment1();
            var channel:SoundChannel = soundSegment1.play();
Then, in my main.as, I have done several attempts to play this sound such as:
var fileLocation:URLRequest = new URLRequest(SWFToLoad); loader.load(fileLocation); loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, progressListener); loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeListener); loader.contentLoaderInfo.addEventListener(Event.INIT, initListener); 
function initListener(e:Event):void // I also placed this code on the completeListener and it didn't work {      loader.content.soundSegment1.playSound(); // doesn't work.  }
I get:
Line XXX 1061: Call to a possibly undefined method playSound through a reference with static type flash.display:DisplayObject.
or, I also read that I should be able to do something like this anywhere in the Main.as file:
var theClass:Class = Class(loader.content.getDefinitionByName("SoundSegment1")); var theSound:theClass = new theClass(); theSound.play()  //doesn't work either.
I also tried on the completeListener:
var TheClass:Class = e.target.applicationDomain.getDefinition("SoundSegment1") as Class; var theSound:TheClass = new TheClass();
theSound.play()  //doesn't work either.
I get:
ReferenceError: Error #1065: Variable SoundSegment1 is not defined. at flash.system::ApplicationDomain/getDefinition()
I am stuck and I really need to get this to work. I would be genuinely grateful for your help.
Thank you in advance for any help provided. I really need to get it to work, because I can't simply embed them in the main SWF or load them individually externally one by one.
Thanks again!

Answer 1

THANK YOU!
I think your code may be over my head though. I think you are using an anonymous function which is not something I am familiar with (but I want to learn about if it's useful).
I also don't know where the classS came from. I see that it's a parameter sent along with the event, but I don't really see where that came from.
Someone at: http://www.kirupa.com/forum/showthread.php?305098-Playing-a-embedded-sound-in-an-external- swf&p=2658098#post2658098
Is showing what seems to be an easier solution, but my problem there is I can't access the source file of the "child" swf....  ayayay.....
I am going to tinker with your solution and see if it gets me anywhere. Thanks so much for your help again.