Fred Astaire's "Let's Call the Whole Thing off"

I'm currently listening to the second disc of a two-disc Fred Astaire set.  In the Gershwin's "Let's Call the Whole Thing off," after the lines "It looks as if we two will never be one / Something must be done," there's an instrumental section (starting at about 2:17).  I'm not sure of the specific instruments, but lines are traded between an instrument with a higher register and one with a lower register.  It continues the back-and-forth that's present in the lyrics:  "You say either, and I say either / You say neither, and I saw neither."