Come hear and play three centuries of keyboards at the Green Room, Saturday, March 29 1:00-4:00 p.m., 62 Bow Street in Somerville. The Green Room, Union Square’s newest art space, is in the unique position of housing three beautiful keyboard instruments: a double-manual harpsichord based on the popular 18th century Flemish style; a square piano by Broadwood and Sons, built in the early 19th century and painstakingly restored; and a modern grand piano from the height of Baldwin’s manufacturing from the middle of the 20th century. Visit the space to not only see three centuries of keyboard but get the opportunity to hear the instruments professionally played and even get to try them out yourself.