What is a continuous free reed organ?
Technically, all Wurlitzer reed organs are free reed organs, because their reeds vibrate freely in air. The reeds in continuous free reed organs are always vibrating; on the other hand, the reeds in keyed reed organs only start to vibrate when the key is pressed. For this reason, keyed reed organs have a slower attack.
The development of the free reed organ was hailed by Richard H. Dorf as a major improvement. Announcing the new Model 44 in the December 1954 Radio-Electronics:
What particularly distinguishes the model 44, however, is the fact that all reeds are blown all the time at low air pressure. The keying is done entirely electronically, resulting in the elimination of the characteristic slow speaking of reeds which has bothered some people. The system tends to reduce mechanical ciphers, too, because dirt has little chance to accumulate on a reed that is waving in the breeze all the time. Electronic keying also makes the keying much simpler, doing away with both direct action and its Rube Goldberg lever system and electrical keying with its solenoids by the ton. Another advantage is that attacks may be made as sharp or as delayed as the designer wishes.