"Call-and-response" slang

[Wilson Gray]

Back in the middle 'Fifties, there were some slang expressions that
consisted of two parts: one person said one part and the other person
replied with the other part. The calls continue, more or less, to be
used today, but, for some reason, the responses have been lost. A
couple of examples are:

Call: Hang loose!
Response: Swing easy!

Call: How are they (understood to refer to one's testicles) hanging?
Response I: Side by side, for power!
Response II: One behind the other, for speed!

I haven't tried to keep count, but, it seems to me, "How's _it_
hanging?" is, today,
heard _far_ more often than what is, for me, the original version.

-Wilson Gray