If I want to have synchronization of my visual effects to the background music as I understand it the best way is to analyze the background music offline, add time markers and parse this marker file from XNA. My question is if anyone know the easiest approach to generate this marker file?

Ideally I would prefer a free program that visualizes the music so I can add markers and export these to a text file. Does something like that exist? I know this isn't specifically an XNA question but maybe someone could give a hint anyway.

I have finally found a good solution to my problem and I guess it would be ok to share it with anyone who stumble on this thread.

After a lot of googling I found a free audio editor program named Audacity and it does everything I was looking for.

It can visualize the music and I can add markers that can be named individually and exported to a text file. It can even auto detect the music beat and add markers itself. As an added bonus it can generate its own beat that I can export to WAV for test purposes. All in all what I was looking for.