A motley crew…
Are you, too?
They were playing Pink Floyd — “Another Brick in the Wall.”
The “writing on the wall” refers to the assassination in March 2012 of Bernardo Vásquez Sánchez, a Zapotec community activist who had spoken out against a Canadian owned gold mine in San José del Progreso, Oaxaca.
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View From Casita Colibrí 
Those two guys are great! They do some lovely & subtle things with songs.
I have some video of them with a bass player and singer playing on the Alameda on election day, that I eventually plan to post. 😉