Foreigner and Air Supply are booked later this spring. The first ticketed act, Jefferson Starship, is set for February 27 at the Casino at Dania Beach, which opened last month and features Stage 954, a new concert hall with 850 seats. The new casino at Dania Beach will focus on classic rock, with some comedy thrown in. You should be able to follow this one fairly easily: The average slot player is at least 50 years old. In addition to slots, casinos like to offer entertainment - including music. Ergo…