A State Of Trance (often abbreviated as ASOT) is the title of a weekly radio show hosted by prominent trance producer DJ Armin van Buuren. First airing in March 2001 on ID&T Radio (the predecessor of Slam!FM), the show takes the format of a two hour mix in which he plays new trance music, both promotional and commercially released. Selected tracks are announced during the show in order to help promote new artists and releases. Its radio-show/website combination has proven popular internationally, as fans—while listening to the radio-show—will converse in the website chat-rooms and forums, such as Digitally Imported, during the broadcast. The success of the show has also spawned to include several parties around the world. In 2011 the 500th episode of the show was celebrated by hosting five different parties on five different continents. ASOT 500 has been hosted in Johannesburg (South Africa), Miami (United States), Buenos Aires (Argentina), Den Bosch (The Netherlands), and Sydney (Australia) between March and April 2011.