In honor of 9/11, small concerts will take place throughout the city. Think "Make Music New York" - it's the exact same idea.
59 small concerts will take place in Manhattan. There will also be ones at Astoria Bagel Shop, Cunningham Park, El Olivo in Astoria, Macy's a QC Mall, Mombar in Astoria, Atlas Park, Socrates Park in Astoria, St. Michael's in Astoria, and Waltz in Astoria. Nothing in Forest Hills.
It would have been nice to be surprised with a "Network Cafe" or "Jade" but they probably didn't know about it (neither did I until this afternoon).
However, per the http://www.septemberconcert.org/ website:
If I don't sign up, can I perform spontaneously? You sure can. Bring your guitar to your neighborhood park. Or stand on a street corner. Go visit a nursing home. Play music for your friends and family in your living room. Please do share with us afterwards, though, what you did, when and where, and we will add it to our records.