I was at the free Rock Lobster concert this Sunday evening. The concert was held in a large grassy area with plenty of room for blankets and lawn chairs. There were several food trucks providing food and drinks. Alcohol is limited to bringing in your own beer in cans although I saw some people with bottles of wine which according to the park's website is prohibited.
The sound system is just OK but the concert was fun. Parking is a real challenge so make sure to get there early!