The quote from Pierre Boulez, given as an epigraph to this article, inspired French researchers to start developing technology for spherical loudspeaker arrays in the 1990s. The hope was to retain the naturalness of sound sources. Now, a few decades later, one might be able to show that even more can be done: In electroacoustic music, using the icosahedral loudspeaker array called IKO seems to enable spatial gestures that enrich alien sounds with a tangible acoustic naturalness. After a brief discussion of directivity-based composition in computer music, the first part of the article describes the technical background of the IKO, its usage in a digital audio workstation, and psychoacoustic evidence regarding the auditory objects the IKO produces. The second part deals with acoustic equations of spherical beamforming, how the IKO's loudspeakers are controlled correspondingly, how we deal with excursion limits, and the resulting beam patterns generated by the IKO.

SpatDIF, the Spatial Sound Description Interchange Format, is an ongoing collaborative effort offering a semantic and syntactic specification for storing and transmitting spatial audio scene descriptions. The SpatDIF core is a lightweight minimal solution providing the most essential set of descriptors for spatial sound scenes. Additional descriptors are introduced as extensions, expanding the namespace and scope with respect to authoring, scene description, rendering, and reproduction of spatial sound. A general overview presents the principles informing the specification, as well as the structure and the terminology of the SpatDIF syntax. Two use cases exemplify SpatDIF's potential for pre-composed pieces as well as interactive installations, and several prototype implementations that have been developed show its real-life utility.