Sound starting and stopping across scenes

New to Flash and under a tight deadline.

I’ve set a music sound to play across three scenes in my movie. However, when the user clicks to enter the fourth scene, I’d like the music to stop. Simple enough.

Here’s the problem…the fourth scene contains individual keyframes in the scene where I have separate voice overs for each frame. The user navs forward or backward among the scene’s keyframes using arrow buttons for forward and backward. How can I have the voice over stop playing on frame 1 if the user clicks the arrow to go to frame 2 if the frame 1 sound isn’t finished playing? Frame 1 plays out until finished, even if the user has clicked to go to frame 2.

Then, on return to the main scene where the general music file played, I’d like it to resume playing upon the user clicking ‘return home.’

Incidentally, I set up my sound files to play on a soundtrack timeline.