I completely agree with you!!! Putting music with lyrics in the video over the top of either spoken or written text creates
competing messages in the same video. The viewer has his attention pulled off of your primary message by the spokesman and put on the lyrics which weakens the primary message. Another example of "unintended consequences".
I listened to the music you are leaning toward using in the video and
damn that is good!
http://www.youtube.com/watch?v=taVW8Kv2HcQ
fight4liberty (F4L)