Volume control of streamed synced sound

I’ve seen many lovely tutorials for creating sliding volume controllers for dynamically inserted audio clips. None of these are really helping me.

I’ve got a movie with a stream-synced music track sitting on its own layer that has to line up with perfectly with other animations going on. I’ve got play, stop, rewind buttons and a progress bar that you can click in to jump to any point in the song. I’ve made a volume controller that slides around just fine, according to a variable it creates at the root level called “volume,” but I cannot seem to make that variable actually change the volume.

Attachsound and setVolume functions seem to be of no avail. Any thoughts?