High Quality Content by WIKIPEDIA articles! Ultra Music Festival is an annual outdoor electronic music festival that occurs in March in the city of Miami usually during the annual Winter Music Conference. It is held in Downtown Miami in Bicentennial Park. It was a 1-day festival from 1999-2006, a 2-day festival from 2007-2010, and was a 3-day festival in 2011. It is one of the highest grossing music festivals in the world. In 2011, over 100,000 people attended the event.