John Butcher is often at his best playing solo because, left alone, he has a way of finding non-sentient duet partners. Whether it's the acoustic properties of the room he's in or the reverb and feedback he can create with saxophone and microphone, he has a deep feeling for making his performances site-specific. The beautiful Cavern With Nightlife (Weight of Wax, 2004) captured a performance in the Oya Stone Museum in Utsunomiya City, Japan, a huge cavern within a mountain formed of lava, to magnificently expansive effect. Resonant Spaces builds on that approach with a tour of Scotland plotted around acoustic potentials. The half dozen locales include a WWII fuel storage tank, an icehouse, an abandoned reservoir, a mausoleum and a seaside cave.

Butcher works intensely with spatiality, creating distinct foregrounds and backgrounds, throughout much of the nine tracks presented here. Some passages feature discernible sax sounds backed by the bouncing echoes of the room. But often it's more mysterious than that. He pops his reed and thwaps his keys underneath the swelling sound bed built from natural delays of as much as 15 seconds, or against the complements of seagulls overhead. In an Orkney island field, Butcher even steps back, allowing a heavy wind to play his amplified horn. Once the sonic possibilities become fixed, the performances can even eclipse the performer; at times any conventional feeling of any musical instrument disappears and, like a variation of Alvin Lucier's I Am Sitting in a Room, the impression is of hearing the geometry of space. With the assistance of tour producer Arika, Butcher has created a rich and fascinating sound document.