They announced last week the rain site is Niskayuna High School. I would check their website http://www.musichavenstage.org
Hamilton is playing at Proctor's tonight, so I doubt it would get moved there, but there is the possibility they will move it to the highschool. Any announcements will be on their Facebook page https://www.facebook.com/Music-Haven-Concert-Series-280439965464369/
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