Given comprehension of physical acoustics in concert halls, an accurate replacement to the inadequate concatenation of reverberation theory, geometric acoustics, and Beranek’s “perceptual categories” that long has held the field in architectural acoustics, it remains to explain how the symphony orchestra couples to the space. Individual instruments do not couple to the space directly, but first to others in their respective sections: first violins to first violins, second violins to second violins, violas to violas, cellos to cellos, basses to basses, and so on through the winds, and others. Each section is synchronized in phase by a Kuramoto mean-field. Then the coherently radiating sections couple to each other asynchronously and create a unique propagating field according to the Sommerfield radiation condition. Kuramoto mean-field coupling is key, for absent that a section’s individual instruments would tend to randomize in phase and sum to zero power. The Sommerfeld radiation condition does not guarantee such a uniform field, only a unique one, the power and information of which are conveyed to the audience as constrained by the usual Gabor-Huygens principle: proximity effects and resonant scattering are essential.