I remember the teacher in my beginner's class pointing out that the CD for sale didn't actually include the music used in class (Lou Bega, Ricky Martin, as mentioned above) - it contained what she called "real salsa" music. I didn't recognise most of the music used in class.
The music used by the teacher in the "el segundo" class I attended was very different - when her CD worked that is......I left after 3 weeks!