Barbara, I was reading the material at your link to watchtowerdocuments, and I read this about the organ:
In 1931, the WBBR studios were moved to 122-126 Columbia Heights in Brooklyn. They were situated in a rear building near Furman Street. In 1931 they installed an organ, a Gottfried formerly from WHK in Cleveland.
The organ came from WHK, another radio station.
WHK was a radio station that had been purchased by Rutherford in 1924 and sold in 1934 for $250,000. After the sale, Rutherford was sued by the fellow JW who claimed he had been the one to put up $10,000 (half of purchase price, apparently) to buy WHK and Radio Air Service Corporation.
Another radio station which the WTS doesn't include in their history books - KFWM (from the same link - http://jwdivorces.bravehost.com/rutherford2.html ):
KFWM-AM in Oakland, California was licensed as a commercial radio station, and went on the air for the first time in July 1925, under the ownership of the Oakland Educational Society. KFWM was devoted exclusively to religious content provided by the WatchTower Society -- Bethelites and Pilgrims from WatchTower HQ, and "Bible Students" from congregations all over southern California. Part of the Oakland Educational Society building (formerly the Pilgrim Congregational Church) contained the equipment and outside tower for KFWM, while the large sanctuary and other portions of the building served as Oakland's first owned "Kingdom Hall". Online sources refer to the Oakland Educational Society building specifically as the "International Bible School", the "I.B.S.A. Auditorium", and the "I.B.S.A. Temple".
KFWM's corporate "President" was Henry P. Drey, a WatchTower Pilgrim and onetime Bethelite, while the corporate "Vice-President" was W. R. Fraser, who was a known "Bible Student". Other station employees included another WatchTower Pilgrim, Gordon R. Pollock. Readers should review all of their WatchTower history sources to understand that the WTBTS has never, ever claimed ownership of KFWM. The WTBTS merely has claimed a "contractual relationship" with KFWM to provide "biblical content" for this radio station's programming, which was the "excuse" provided to the government and general public for the station's religious format, and the fact that every person connected with KFWM was also somehow connected either to the WTBTS, or one of its local affiliates. In 1925, whom is the sole person who had the authority and ability to bring all of this together -- only "Boss" Rutherford. It is a certainty that all of these WatchTower Society personnel and local "Bible Students" served as "straw-men" to keep "Judge" Rutherford's personal ownership of KFWM a secret from both the general public and the government.
Frankly, online ownership info pertaining to KFWM is so contradictory, sketchy, and incorrect, that we will not attempt to provide a definitive history of such (no doubt partially caused by efforts to hide Rutherford's changing ownership interests over the years). What we do know is that over the years that KFWM grew and flourished. From its founding in 1925 through 1929, for all intents and purposes, KFWM was WBBR-WEST. However, in January 1930, "Judge" Rutherford sold part of the operation to unknown parties (probably once again a local newspaper), which again resulted in the formation of a new corporate owner -- EDUCATIONAL BROADCASTING CORPORATION. Thereafter, additional real estate, including satellite locations, were acquired, and the station's call letters were changed. Notably, however, "Bible Students" H. P. Drey and W. R. Fraser continued to run the station as corporate "President" and "VP. However, with the addition of non-JW owners, KFWM ceased being WBBR-WEST, and simply became one of many radio stations that occasionally broadcast WatchTower programming. Finally, in 1939, there was another major sale, and this one appears to have resulted in the departure of most of the "Jehovah's Witnesses" left at KFWM. But, who knows. Even after some other group took over management of the station, Rutherford may still have retained a minority interest.
More radio history here: http://jwdivorces.bravehost.com/rutherford2.html "Judge Rutherford's Personal Radio Empire" starts about 3/4 of the way down the page