"This photo is at Union Square on the South Plaza. These Mass Appeal events are for musicians who don't have bands to play with but they still want to participate. They can just show up with their instrument, at a particular time, at a particular place, and there's someone there to lead 80 trombones or 200 guitars.
With guitars, there are so many guitar players that a large organization was needed. The New York City Guitar School organized this event and there was a second guitar event at the 92nd Street Y on the Upper East Side. For the Union Square event, the Guitar School wrote the chord changes on large pieces of poster board, and these were held up when it was time to play that particular chord. So you don't have to have individual music stands for everyone; although they do have charts that people can download and bring with them. They've been doing that for three years and can accommodate any number of performers. They actually have practice sessions at the New York City Guitar School for absolute beginners. Guitarists can also look on the website to see which songs they'll be expected to play. But if you just show up, you'll still be able to see the chords, follow the leader, and play along."
All quotes by Aaron Friedman
Photo courtesy of New York City Guitar School