The $585 million Music City Center proposed for downtown Nashville won final financial approval yesterday by a vote of 29-9 from the Metropolitan County Council, Nashville's legislative body, after about a decade of debate and study. Construction will take about three years, and there are 26 advance bookings already in place, totaling 280,000 room nights. According to the plans, the 1.2 million-square-foot center will have 350,000 square feet of exhibit space, 90,000 square feet of meeting space, 75,000 square feet of ballroom space and 30,000 square feet of retail shops. In addition, a 1,000-room convention center hotel with 100,000 square feet of meeting space is being planned, though financing for that project was not addressed at the council meeting.