Are Moonbabies at the head of an underground Midnight Oil appreciation league? On War on Sound — their post-Orange Billboard mini-album — Ola Frick and Carina Johansson perfect the grace of Blue Sky Mining’s “Stars of Warburton.” They linger tenderly on its urgent chorus lyric, and tune down considerably the Peter Garrett self-righteousness. “Don’t wanna talk about Elvis Presley/Don’t wanna see his white shoes walking around” — the punchy drum loop and tumbling acoustic guitars are pretty Sparklehorse’ing great, too. “Warburton” isn’t the only cover version here — Pink Floyd’s “Arnold Layne” drifts between a stoned Blur and the haze of some faraway galaxy. Elsewhere, War on Sound offers an alternate version of Orange Billboard’s title track, as well as five songs unique to this set. “Perfect Passenger” and “Don’t Shoot the Ranger” are instrumentals; they seem a little like sketches, but that’s okay for a tide-you-over record. Meanwhile, the intimate “Minor Earthquake” is a standout — just Johansson musing plaintively over the piano — and the opening title track is War on Sound’s most fully realized moment. It’s another strong effort from this underappreciated Swedish duo, who keep clearing pathways between indie pop and places without a postcard. – Johnny Loftus