the possibilities are endless in flash
but consider this
if you have
scene 1 (Preload)
scene 2 (intro)
scene 3 (main)
scene 4-8 (Info)
All are in the same time line.
if you make a key frame with sound/music sync to event or start and loop it say 8 times and add fade out it will play and fade and and play and fade etc.
it won't play 8 times and on the 8th time fade out.
You may want to make small movie clips with just the loops/music in them and drop them in to the scene that you want them to play in and give them and instance name.
Then you can control them with Tell Target.
That might do the trick.
Like i said there are endless possibilities
so you'll just have to experiment.
I am going to work on some of this kind of stuff soon.
right now im working on a web site, 2 games,
and a Flash Player.swf that loads seperate .swf files that contain audio loops.