Synchronized Sound

I have just started using Flash MX wanting to build a visual sequence to fit an mp3 song. I would like to be able to use the soundtrack as a guide and influence over the animation’s content building it up as I go.

With this in mind, I have loaded an mp3 into the Library, created a dedicated layer for it and pulled the graphic waveform onto the stage.

In the Timeline - the audio representation can be set to various lengths. However, when I drag the red frame indicator over it I get no audio relay - although the graphics advance as expected.

When I try “Control” and “Play” - I DO get sound but too much of it as the whole song is played and I can find no way to halt it.

What is the correct method for importing a song to set an animation to allowing for it to be easily edited to ?