It comprises many events, usually including opera, theatre, dance, classical and contemporary music, cabaret, literature, visual art and new media. The four-day world music event, WOMADelaide, and literary festival Adelaide Writers' Week are also part of the Festival. Originally presented biennially, along with the (initially unofficial) Adelaide Fringe, the Fringe has been held annually since 2007, with the Festival of Arts going annual a few years later, in 2012. With all of these events, plus the extra visitors, activities and music concerts brought by the street circuit motor racing event known as the Adelaide 500, the time of year is often referred to as "Mad March" by locals.