A decade ago, Wolfgang Voigt’s Gas project was the be-all end-all of ambient techno. With the German forest–his old LSD playground and an icon of his country’s folklore–as his muse, he converted samples of arcane, orchestral melodies into some of the most mesmerizing loops ever heard. Nah Und Fern collects all four Gas albums, threading together the records’ fluid drones and skeletal, drifting beats. But certain moods mark each album: Where the eponymous debut and Pop are full of day-lit optimism and spiritual awe, Zauberberg and Konigsforst are haunted with dread and moonless atmospheres.