Synchronize Program Event with Music Playback

I have been searching and googling this for several weeks...however I cannot seem to find any clear solution.  I have a dynamic display that needs to be changed as a musical piece is played...how can I get access to the sound card buffer data?  Or is this even the right method?  Any comments or suggestions are greatly appreciated...

Chris that music is played with your applications or it is played by some other application running on system.

For now, it can be either...I could launch it several ways but it would be Windows Media Player or some other player I would be using.  I am fully open to suggestions at the moment.  Playing music is easy!! lol

If the piece of music is played by our own application then we would know what is going to be played but if music is played by other outer application then to capture data from that application will be little tough.
I would see I can get some solutions for you.

for the moment, I am reading in PCM data from a wave file.  I can work with the data and I can play it via another program.

1.  I am not sure how to "play it myself"

2.  I have no way of keeping it sync'd to what I want to do.

This app is in its early infant stages and this is the last MAJOR hurdle (at least I think)