Supervia sings "Musetta's Waltz" in 1934 film "Evensong" 

"Evensong" -- a British film (directed by Victor Saville), adapted from a tell-all novelization of Nellie Melba's life, with a plot resembling "All About Eve". The Eve Harrington/Anne Baxter character is the great Spanish mezzo, Conchita Supervia (1895-1936). Supervia plays "Baba L'Etoile", the young rival of the aging British has-been "Madame Irela" (Evelyn Laye), who refers to the younger singer as a "Spanish cow". Supervia has a very small part in this film, but most of it is singing, and her distinctive vibrato is in full throttle here.