planetrock MCM is ceasing production of Planet Rock as of the 29th of November while American Top 40 will finish at the end of December. Take 40 is changing format on December 5, with MCM deciding that stations can only play it on Saturdays between 2-6pm. MCM wants a 12 month commitment to the show, however this could play havoc with stations that take live sport such as NRL and AFL during the winter months.