The acoustical effects achieved and the techniques used in the radiation of organ tone are quite different from the conventional effects and practices of public-address sound systems. For the latter, point-source radiation with high uniform directivity and a minimum of reverberation are sought, in general, for the creation of the illusion of “presence” of the original sound source. However, in organ music the sound sources are distributed in space. Individually the sources are quite complex in their directional pattern, and collectively their sound distribution is diffuse. This is especially true in those typical cases where the tone sources are enclosed in an organ chamber or box or are installed in a highly reverberant environment. Another distinctive feature of organ tone radiation systems is the relative importance of the octave below 60 cps, a frequency range frequently neglected even in sound systems designed for general musical purposes. In this paper the design principles of organ tone chambers and the types of organ tone cabinets in use are reviewed. Organ installation principles and examples of their application are given. The implication of these principles with regard to optimum reverberation for church auditoriums is discussed.