This collaboration between Icelandic composer Olafur Arnalds and German pianist Nils Frahm emerged from a single late-night improvisation session in Berlin, captured on film and released as both album and documentary. Arnalds and Frahm had been friends and occasional collaborators, sharing approaches to music that blend acoustic instruments with electronics, minimalist composition with ambient textures. For this project they simply played together in Frahm's studio, letting the session unfold without predetermined structure. The resulting music moves between piano meditation and synthesizer atmosphere, neither musician leading but both responding in real time to what the other creates. The accompanying film shows them at work, revealing the intimacy and concentration of improvised collaboration. Both artists have developed distinctive voices in contemporary classical and electronic music: Arnalds through his scores and productions, Frahm through his live performances and studio albums. This project captures a moment before either had achieved their current visibility, two friends making music with no commercial pressure or artistic agenda beyond the pleasure of playing together. The recording demonstrates how constraints--a single session, no overdubs, minimal editing--can produce work more vital than carefully constructed studio productions.