If you want to see an example of a blog with an invisible music counter, surf over to Blog with invisible background music with automatic play with your speakers turned on.
For instruction how to add an invisible background music player to your blog, refer to How to install an invisible music player and why you should not do it.
Hot linkable file host and embedding music player
How to add music to your blog
Add MP3 player to your blog
Easy way to add music to blog (eSnip)
eSnip music player in sidebar
Make music slideshows with Fliptrack
Music at Amazon