After only one EP, a seminal album (“Vs.”) and a posthumous live album (“The Horrible Truth about Burma”), one of the quintessential US indie rock bands of the 1980s split up. Almost twenty years later, Mission of Burma reunited and released the powerful “ONoffON” in 2004. Now, after recording and playing live regularly for the past eight years, the band released their fifth album, “Unsound,” through Fire Records. Experimental as usual, yet at the same time catchy and accessible, “Unsound” presents eleven new post-punk songs in just under 35 minutes. And although Mission of Burma’s brand of post punk will never be considered as radio-friendly as, say, Franz Ferdinand, these eleven short and to-the-point tracks are among the band’s strongest material to date. Advance single “Dust Devil” and the mid-tempo rocker “Semi-Pseudo-Sort-of-Plan” are two good cases in point. Dizzying noise loops still feature heavily on tracks such as “This is Hi-Fi,” and neither have they given up on their anthemic side – “Second Television” and “Part the Sea” easily fall into this category. The intricate groove of “Fell-->H2O,” Prescott’s adept drumming on “ADD in Unison” and the driven intensity of album closer “Opener” make these three songs instant favorites. Recorded by the band with Bob Weston (of Shellac) at their own Boston practice space, “Unsound” is a true indie rock album. As Mission of Burma prove on their latest album, some bands don’t get old, they just get better.