This is an Add-on for the Napoleon: Fields of Glory modification.
This Add-on changes the marching drum cadences for Napoleon: Total war.
This is a slightly outdated video however the differences in the new version are only slight.
Download and have a go.
NEW Download Version 2.0 NEW
Napoleon: Fields of Glory mod link below. . .
http://www.twcenter.net/forums/showthread.php?t=499906