In addition to the multiple pianos installed on the
Olympic-class, a large pipe organ built by Welte Philharmonic was planned and built for Britannic. There is *some* debate as to whether it was installed aboard before the ship's hospital ship duty.
It was restored by a Swiss museum in 1969, and they found the ship's name on many of the parts which indicated its origin. There are several articles with more background on this organ, and even YouTube clips of it being played.