This is a song from the forthcoming Rotifer album "The Cavalry Never Showed Up", inspired by the primitive sailing vessel called "optimist" as used in sailing courses at foundation level. Written shortly before the band went into the studio, Robert played this song to Mike and Ian at the recording session, and this is the three-piece live-in-the-studio version they recorded on the spot, plus some splashes of lapsteel added later on the same day by Paul Rains of Allo Darlin' pop renown. So it's not quite dogma in a strict von Trier sense after all.
By contrast, the completely undogmatic album version will feature some acoustic guitar on top, as well as other minor embellishments.