On "You Can't Do That On Stage Anymore Vol. 4" the song entitled "Johnny Darling" the part where they sing (as you've described) "Wah-ah-ah hoo-oo" I'm pretty sure is a quote from "There's a Moon Out Tonight" by the Capris. Here is the song if you'd like to check it out for yourself: http://www.youtube.com/watch?v=P4xNF9uh8SA.
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