Holy Trinity Church of Cambridge, MA, and the Erevan Choral Society and Orchestra will present a “Christmas Holiday Concert” on Sunday, Dec. 15, at 7 p.m. in the church sanctuary (145 Brattle St., Cambridge). This year’s concert will feature Metropolitan Opera soprano Tatev Baroyan, and tenor Fr. Ghazar Bedrossian, who will join the chorale under the baton of Maestro Konstantin Petrossian. Open to the public, admission is free. For information, click here to view a flyer; contact the church office at (617) 354-0632; or e-mail office@htaac.org.