In 1973, a rock guitarist and an electronic knob-twiddler released a revered and trail-blazing document in contemporary ambient music: Robert Fripp and Brian Eno’s No Pussyfooting. Thirty-five years later, guitarist Richard Pinhas and noise artist Masami Akita (aka Merzbow) have formed the 21st-century version of the concept. Keio Line, a double CD released by Silver Spring label Cuneiform, captures a whirlwind two-day collaboration between the French ambient guitarist and the Japanese experimental-music legend. The bulk of Merzbow’s output is such that one might expect Akita to dominate any project in which he is involved, but Keio Line is something of a curveball: Merzbow’s grating noisescapes are, if not subdued, then at least submerged, like an insistent undertow lurking beneath the relative calm of Pinhas’ looping guitar. The album’s six long tracks, ranging from eight to 26 minutes long, are sprawling ambient epics that function well as background music but also reveal layers of detail upon closer listening. Most frequently, Pinhas’ guitar loops are the first layer to emerge; his drawn-out, slowly modulating tones—which are evolved from Fripp’s techniques—sound like a natural extension of his most recent work on solo albums like Tranzition and Metatron, though here he’s dumped the spoken-word as well as live and programmed drumming. More interesting are Merzbow’s contributions. There are no punishing gales of pure noise a la 1994’s Venereology, and his recent rhythm experiments in the “Merz-” series (Merzbeat, Merzbear, etc.) are similarly absent. Instead, Akita’s electronics emphasize subtle rumblings, vaguely rhythmic churnings that serve to provide texture and counterpoint to Pinhas’ extended ruminations. Even when Pinhas drops out of the mix, Merzbow’s industrial-sounding electronics stay at a relatively low volume, in keeping with the ambient nature of the recording. Through their collaboration, Merzbow pushes his music into the background in much the same way Pinhas draws in listeners. Keio Line comes impressively close to Eno’s ideal of ambient music as something that is “as ignorable as it is interesting.”