The group's evolution is firmly signalled in the opener, Structure 1. There's a lush, romantic quality to the playing and arrangement that we've not heard before: the guitar licks have a bluesy lilt, the bass imparts melody as well as physical presence, the synth sequences are more painterly, looser somehow, and Ripatti's percussion roams feelingly.
Structure 2 is like 70s spy-flick jazz or groove-heavy Krautrock stripped to its barest essence, Loderbauer and von Oswald's electronics glistening in a sticky cobweb of reverb and delay. The languidly stepping Structure 3 faintly recalls von Oswald's work with Mark Ernestus as Rhythm & Sound, with St Hilaire's chords hanging thick above bone-dry drum machine drift. Lastly, Structure 4, the track structurally closest to techno, is pervaded by a sense of mischief, with Muellbauer's strings — plucked, bowed, scraped — coming to the fore.
For all its complexity, this is also a very playful album, and the Trio's increased confidence and empathy as improvisers allow them to indulge flights of percussive fancy, sudden about-turns, vectors into the unknown. Horizontal Structures sounds, above all else, free.