I would sit out on the sea wall playing my acoustic guitar. They seemed to really like 12 bar blues chord progressions in about any key. When my family came to visit me on the launch campaign I was playing my guitar to get the dolphins to come by. They showed up as usual. When my daughter started playing her violin they went absolutely nuts. She played for the the dolphins for over an hour. It was one of her longest practice sessions ever. Something about the violin really got them excited.