The four letter answer to the crossword clue 'Maria Singers in 'The Sound of Music'' is NUNS. The 1965 musical film 'The Sound of Music' follows the story of Maria, a young nun who leaves her convent to become a governess for the seven children of a widowed Austrian naval captain. In the movie, Maria and the other nuns sing several songs together, including 'My Favorite Things' and 'Climb Ev'ry Mountain'.