I just took my 4 month old son to My Gym for a baby class, and we had so much fun!
The class started out with all of the babies on blankets with balls. There were five babies and two instructors in the class. We did some baby warm-ups, which consisted of the parents moving the babies' arms and legs around in various ways. Then we did songs with the babies, tummy time with toys, danced with the babies, put them in swings, on a baby zipline and then played with puppets! It was a jam-packed 45 minutes, and my son really loved it. I would recommend this place to anyone.