Adding music to the game

I've converted some tracks from the Lord of the Rings soundtracks into .wav files and inserted them into the playlist. I think I've done everything right but its not working in the game. I have a couple of questions.

1) Is there a limit to how big a track can be or how many you can add? (I know you can have 6 for each section in the playlist and I haven't exceeded this)

2) Can you call the tracks what you want or do you have to call them '? Tension', '? Lose', etc?

Thanks in advance.

Someone from CA explained it in this thread:
Battle music

I followed these instructions and added the Mongol music in Shogun to MTW. Except for the "tension"-music it worked fine.