Follow That Bird

Recently, my friend Arnold was discussing character actor Walter Slezak ("Lifeboat," "The Pirate," "The Inspector General") and cited this anecdote about the man's father, found at IMDb:

"He [Walter] was the son of Leo Slezak, operatic tenor (Aug. 18, 1873 - June 1, 1946), later a comedian in Austrian films. Leo Slezak was a famous Lohengrin, and is credited with this story: during one production of the opera 'Lohengrin,' when the mechanical swan that was to carry the hero across the lake malfunctioned and 'floated' off too soon, he was heard to say, 'What time is the next swan?' This quote became the title of Walter Slezak's autobiography."