Running nearly 70 minutes, Centralia is a sprawling and hypnotic journey. The duo of Koen Holtkamp and Brendon Anderegg creates a plaintive and moving work from disparate parts woven together with great care. Understated and contemplative, Centralia is a celebration of subtle interactions. The interplay between synth drones and hypnotic acoustic guitar and piano melodies blurs the line between organic and electronic. On first listen, the music seems to rarely waver. Yet subsequent listens reveal many unexpected and startling moments, such as the cello passage near the end of “Sand” and the gentle warble that rises to the surface midway through the 20-minute centerpiece “Propeller.” Centralia is a captivating tour de force that stretches the boundaries of ambient music.