This is from the BMI FAQ page:

There are two other performing rights organizations in the U.S. If you play the music from either of these organizations, then you must have separate licenses with one of both of them; or, you need to get the permission of the individual copyright owners whose works they represent.

Here's the problem from the point of view of the club owner - even if he pays for a license from one, the other two can come after him. And with licenses from all three - there is still the potential for songs to be performed on his stage that he needed to get permission from an individual copyright owner.

Marty my home

Experience is that marvelous thing that enables you to recognize a mistake when you make it again!