The fifth season of the sitcom ended with its characters mounting a community theatre production of the 1966 musical.
The episode, which premiered April 10, featured performances of "Willkommen" and "Maybe This Time." Star and co-creator Dan Levy co-directed the episode with Film Forge’s very own Andrew Cividino.
Source: http://www.playbill.com/article/go-behind-the-scenes-of-schitts-creeks-cabaret-themed-season-finale