On the Wynton Marsalis album "Live at Blues Alley" there is a song that they play three times during the set. The song is called "Juan" the first time through. The second time it is titled "Juan (E. Mustaad)" and the third time it is titled "Juan (Skip Mustaad)." At a point near the beginning of the song the band chants something. On the first one they say, "Juan, Juan," then something I can't quite make out. On the second one they say, "E, E," then the same phrase. On the third time they say, "Skip, Skip," and the same phrase.
As soon as they say it on the third time there is a reaction from the audience. The phrase obviously has some sort of joke implied which the audience clearly understands, but I do not.
You can hear it about ten seconds into the following video. They then repeat it a few seconds later.
What is the phrase they are saying and what does it mean?