If you haven’t heard of them, the Open Space Alliance is a (relatively) new group that was been formed to serve as an advocate and conservator of north Brooklyn’s parks – including McCarren Park, the yet-to-built waterfront esplanade, the yet-to-bought City-owned waterfront park, and more. OSA is yet another benefit of the Greenpoint/Williamsburg rezoning (and yet another community-based benefit – the benefits promised by the administration and the Council seem to be a bit slower in coming). OSA is in the process of hiring an executive director, and is introducing themselves to the neighborhood with a benefit concert on Saturday, 15 September. Hosted by JellyNYC, which has been putting on free concerts at McCarren pool for the past two summers, the OSA benefit features GZA playing Liquid Swords and Jamie Lidell. The concert is $19, all of which benefits OSA, and ultimately, your parks. Ticketmaster has the tickets. And while you’re at it, fill out the OSA McCarren Park Pool survey – add your voice to help shape the future of the pool.