A historic 1894 Hook & Hastings Opus 123 organ will be featured when Brandon Santini performs in First Congregational Church of Rockland on Sunday at 3 p.m. The organ was designed and custom-built for the church and consists of 18 ranks, which total 982 pipes. Santini, who has performed around the world, is the organist and music director of St. Theresa of Avila Church in West Roxbury. The concert is part of the 200th anniversary of the church. A $5 donation is requested. For more information, call 781-878-0060 or visit www.firstchurchrockland.org.