JohnL is correct.
This is a spin off of original event started in CA. Now up to 7 cities.
I believe Dr Perez was a member of Bones West and part of original Tbone Xmas events. This was 2nd year in KC. I did not play last year as I just starting playing again this past May. This was the first mass bone ensemble i have played in since 76+4 Trombones in Vegas in early 90's.

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It was a very live venue acoustically. I could barely hear myself or my stand mate. I mostly heard the guy behind me on my left playing 1st part and the guy behind me on my right honking away on Bass. Lets just say that most of the written dynamics may have been avoided by the whole group.
I will try to get a video or two up later this evening. I think my wife recorded some on her phone. Thanks