While the theme of the four elements has been a constant source of inspiration in the arts, its setting to music using electroacoustic techniques seems highly auspicious, since the notion of matter and its transformation is consubstantial with the concrete approach. In »Sphæra«, Daniel Teruggi precisely addresses this question, transcending matter with the help of novel digital audio techniques so as to draw out forms, trajectories, layers, and musical objects, all of which result from the merging or sublimation of primordial sounds. Indeed, this is where Daniel Teruggi’s music and compositional approach stand out: by engaging sounds, with strength, will and inspiration, in a close encounter with energies, whether tectonic or electrical. Such collisions, such metamorphoses, are then appeased in the whole space of the composition, a fascinating landscape, the final destination of all transmutations. (François Bonnet, Paris, 2021)

"Between 1984 and 1989, my acousmatic work was focused on processing and merging the four fundamental substances. Each 'element' gradually became articulated with the others, thus crystallizing my subjective perception of their materiality. Over the years, helped by the enthusiasm of a Greek friend who propelled me into the Socratic universe, what started out as an exploratory path has become a circular, spherical unity, in which each occurrence simultaneously belongs to one of the four substances as well as the whole.
These four sections, of uneven durations, embody the different resonances of each 'element' upon my imagination. The movements are ordered compositionally and range from the intangibility of the air to the extreme density of the earth.
In Eterea, the dual nature of air, a space for the dissemination of sounds and an environment for mobile masses, shaped the work and the development of its forms. Whether it be the vast expanse of particles as organised movement or the displacement of sources in our three-dimensional perception, ethereal air fills the space and drives the immaterial motions and gestures." - Daniel Teruggi