As a gentle rain poured over eastern Long Island early Sunday evening, a packed sanctuary of concertgoers at Bridgehampton’s Presbyterian Church reveled in Alan Alda’s delightful readings of excerpts from Wolfgang Amadeus Mozart’s letters, interspersed with top-notch performances of the composer’s chamber works K. 13, 285, 548 and 493 by world-renowned musicians. Alda, the actor, director, screenwriter, author and currently a Visiting Professor at Stony Brook University, enlightened the audience with some of Mozart’s most humorous, passionate, personal and sobering musings. The performance, which will be repeated August 1, opened the annual Bridgehampton Chamber Music Festival, which celebrates its 33rd year and continues throughout the month of August, at various locations throughout the hamlet, easily reachable via Route 27 east. For more information on the festival, go to: http://www.bcmf.org/. Scores and recordings of the aforementioned works, and Mozart’s published letters are available in the Melville Library’s Music Library.