The collaboration between Frey and Quatuor Bozzini is close. Violinist Clemens Merkel and Frey have known each other since 1990. Furthermore, the quartet previously premiered the second string quartet from the late 1990s and recorded the first three quartets for Ediotion Wandelweiser. With this five-movement fourth quartet, the collaboration went a step further, Frey explicitly involving the string quartet in the process of composing. The first movement is very slow, but also very even, with the sounds coinciding remarkably. Also special are the subtle but very exciting string movements in this first movement. The second movement stands out in particular for its repetitive pattern, sounding pretty much like a siren, while the third movement, which begins quite brightly, stands out for its melodic content, something we don’t often encounter with Frey. Following this, the fourth movement again sounds broodingly exciting, with its hushed string movements. Finally, we hear the impressive fifth movement, which at over 30 minutes is about as long as the first four movements. Beautiful, quite similar patterns, like a quietly flowing river.