The song Susannah and Ira perform in the club is "Where have you been all my life", a song written by Cynthia Weil and Barry Mann.
(Ursula tries to reconstruct the chalkboard menu from memory)
Ursula: What day is today?
Ursula Then the soup is (long pause as she thinks) du jour.
The episode won an Emmy Award for Outstanding Sound Mixing for a Comedy Series or a Special.