Soprano Christine Letcher, mezzo-soprano Andrea Graichen, and bass John D. Adams present highlights from Handel’s rarely-performed Aci, Galatea e Polifemo plus 20th century American songs and Broadway tunes with harpsichordist/pianist Sean Fleming, lutenist Timothy Burris, and the Longfellow String Quartet; Friday, September 18 at 7:30 p.m. at the State Street Church Chapel; Sunday, September 20 at 2:00 p.m. at Snow Pond Center for the Arts