Michael Karoli of Can and Faust’s Uwe Nettelbeck are dead; Kraftwerk are today reduced to founder Ralf Hütter and a crew of minions; but at the respective ages of 75 and 65, Hans-Joachim Roedelius and Dieter Moebius continue their musical work as Cluster. Mind you, Cluster never quite fitted into the “Krautrock” category, being principally involved in the field of ambient electronica. (in their more grandiose moments they have all but claimed that their mid-1970s collaborations with Brian Eno taught him all he knew in that area.) They celebrated the release of their first studio album in 14 years, Qua, with a low-key concert in a central Berlin arts centre.

Visually, there was little to arrest, as they took their positions behind their modest but versatile arrays of oscillators, filters, modulators and now also samplers and looping units, plus a mini-keyboard each. Roedelius, tall and bald, stood behind one table, looking rather like the kind of schoolmaster who manages to inspire you despite being rather arid; Moebius, opposite him, perched on a piano stool, bending over his devices like an ageing, only partially earnest Puck. In a perverse concession to spectacle, they projected a looped video of a stone farmhouse on a summer’s day. For this was about the music.

And the music was about moments: moments that emerged half-serendipitously from the shifting fabric of rhythms, samples, melodies, noises and effects. This was the kind of “ambient” music that required active listening, as aural images shimmered in and out of focus: at one moment, the sound of a huge wasp buzzing around a Khmer temple; at another, a gigantic turbine thrumming amid a tropical rainforest. Sonic textures morphed into one another without constituting “pieces” as such; the first break for applause came after 42 minutes.

The pair have an instinctive rapport after all these years: a glance, a smile, and they know how to shift matters. It must be said that there was not much here of conventional beauty – their tuneful 1974 Album Zuckerzeit (Sugar-Time) was a kind of contemptuous self-parody – but it is still a privilege to see such masters at work.