A few years ago Michael Brewer, a conductor/PHP/PostgreSQL developer, started leading what he called Geek Choirs at various open source conferences.
From an article about women at the 2014 OSCON conference:
“One of the most memorable of those moments was during Geek Choir, a Birds of a Feather session on Wednesday night. Approximately 16 of us gathered to sing a cappella, starting with simple warm-ups, and moving on to a simple song in unison, and then finally, to more complex songs, sung in rounds. To end our session, we sang Dona Nobis Pacem in a three part round while standing in the large atrium of the convention center. It may have been my most enjoyable moment of the whole conference.
“That I was a woman at a tech conference (or that there were only three of us in the Geek Choir) didn’t matter. What mattered was that we all collaborated to produce beautiful melodies, no sheet music necessary.”
I could see conferences of any sort benefiting from having open choir sessions like this. It’s a great ice-breaker, it’s both relaxing and energizing. Brewer tries to select music than anyone can do, but shouldn’t bore more experienced singers. I know that Dona Nobis Pacem round, for instance. It’s very simple, but so lovely it’s irresistible. After singing people would go back out into the conference more connected to each other and buzzing from that post-singing high. A better conference would be had by all, I’m sure.
Here is Michael Brewer talking about the Geek Choir.
[Video removed because the link no longer works.]