As the name of his New Wave Of Jazz CD label suggests, Belgian guitarist Dirk Serries has, in recent years, concentrated on creating gnarly free-jazz and improv with willing co-conspirators such as UK saxophonist Colin Webster. With his new TONUS project, however, he moves perhaps a little closer to the ambient works he's also known for. Working with pianist Martina Verhoeven and a team of guest performers across a handful of discs, TONUS concentrates on creating minimalist acoustic music that is slow, sparse and spacious – almost to the point of distraction. Cagean Morphology is a 34-mnute piece for acoustic guitar and piano that contains more silence than sound: single, isolated notes separated by yawning chasms of anticipation. Texture Point widens the aesthetic, but only just – expanding to a trio with British viola player Benedict Taylor whose spectral scrapes and ghostly harmonics provide a fragile bed for Verhoeven's Feldmanesque clusters and Serries’ diffident plucks. Intermediate Obscurities I+IV features two discs, each with a live performance by a different sextet. ‘I’, documents an Anglo-Belgium ensemble negotiating the challenge of creating a coherent, hour-long group statement while leaving enough room to make sure that no individual gesture ever overlaps with another, while drummer George Hadow provides a ritualistic backdrop of gently swelling toms and sighing brushes. On ‘IV’, Serries and an all-British cast of collaborators, including Sloth Racket's Cath Roberts on baritone sax, navigate his graphic score, generating crystalline drones and maudlin moans. Serious music for serious times.