The Roosevelt organ, installed in the sanctuary of Trinity United Methodist Church, Denver's first church, received great attention and acclaim, and has proved its lasting worth. The Roosevelt Organ Company was known throughout the world in the 1880s for its blending of innovative technical advancements with serious and solid musical values. In keeping with the congregation's determination to build a sanctuary of the highest possible quality in all respects, the Roosevelt firm was selected to provide the organ. The Trinity organ was completed in December 1888. The façade was designed by the British architect and pipe organ designer George Ashdown Audsley. The $30,000 cost of the organ was donated by one of Trinity's founding fathers, Isaac Blake, who directed the Trinity Choir when the present building opened.
The original specifications for Trinity's organ were remarkably innovative. The key action was electric, with the electricity generated by a dynamo. In order to provide a source of electricity, should it not be available from the city, a water wheel was connected to an artesian well in the sub-basement of the building. The Solo division of the organ is voiced on seven inches of wind pressure. The organ is currently comprised of 4,275 pipes in 82 ranks.
In celebration of Trinity's 150th anniversary, the console was replaced. This newest console provides multiple levels of combination action, MIDI throughout, and the capability to record a performance. In addition, a new unit Bombarde, voiced on ten inches of wind pressure, was added. Today, at an estimated value of two million dollars, Roosevelt No. 380 is one of the largest American-built organs of the nineteenth century still in operation.