Is anyone participating in this program?

The Medicare insurance I'm considering pays for this program and my local Y participates in the program. My question is about the classes. Are they special classes or are you able to take any of the classes offered at the facility? Their website doesn't make this real clear and it almost sounds as if it's just certain classes they offer.

I have a Bally's gym membership and wouldn't want to drop it if I'm limited to special classes at the Y through the Silver Sneakers program. I want to be able to attend at any time they're open, workout on the machines and take any of the classes they offer.