Giacinto Scelsi (1905-1988) was an Italian composer and rather unusual pioneer of electronic music. His works are neither based on traditional techniques nor do they resemble concepts of the 'new music' avant-garde. Since the 1950s he recorded improvisations on the ondiola (an early electronic instrument) to magnetic tape, often in multiple layers. These recordings were then transcribed into scores by his assistants – probably constituting the first attempt at making electronic music heard through acoustic instruments and their players instead of loudspeakers.

Sfera is a dialogue between Jeremias Schwarzer's performances of some of Scelsi's most focused and striking pieces for solo instruments and new electronic works by Stefan Goldmann. The two groups of works are marked by polar opposition and unusual metaphorical proximity at the same time. Goldmann's multi-faceted music exhibits shape-shifting capabilities as liquid as Scelsi's best-known pieces for ensembles or orchestra. However, they make full use of the morphing capabilities of contemporary synthesis, constructing multidimensional movements across a vast parametric space.  The recorder's singular voice forms the baseline for Goldmann's overflowing electronics, which seem to grow out of and fold back into it, as if breathing. Jeremias Schwarzer adapted most of Scelsi's works in this album for the first time for different kinds of recorder.

During the recording sessions he added extensive single-note breath/sound meditations and improvisations in between takes – a stock of recorded material which spills over into the electronic parts (and turns Scelsi's experimental tape methods on their head). A full circle with two tangents mirroring each other.