When the present Fifth Avenue Presbyterian Church was built in 1875, an adjacent two-story Church Annex extended to the west of the Sanctuary. On the ground floor of the Church Annex was a large Lecture Room which included a small organ gallery along the east wall. The Church Annex and Lecture Room were replaced in 1925 by the present 10-story Church House, a facility containing meeting rooms and the present Chapel. The $30,000 contract awarded in 1913 to the Ernest M. Skinner Company included both the large four-manual organ in the Sanctuary, and a small duplexed organ for the Lecture Room. At the request of then-organist Frank L. Sealy, the smaller organ included console and chest preparations for two additional stops (Cornopean and Unda Maris), but these stops were never installed.

Identified through information adapted from E. M. Skinner/Aeolian-Skinner Opus List, by Sand Lawn and Allen Kinzey (Organ Historical Society, 1997), and included here through the kind permission of Sand Lawn:
Two manual Chapel organ included in contract; altered in 1945, #A-864 and 1955, #A-215, chapel organ replaced by #514 in 1925.