“Here’s my song for the free/No, it’s not about praise and publicity,” Serj Tankian sings. He ain’t kidding: Serj Tankian is beholden to no master beyond his own outsize ambitions. The System of a Down frontman’s second solo disc sets lefty harangues (“Corporate-ocrasy, what a hypocrisy!”) to symphonic, electronica-tinged prog-rock that makes SOAD’s wildest metal moments seem almost Bieber-esque. Tankian’s constant (and erratic) genre-busting can be tiring. But his happily maniacal, syllable-drunk delivery gives songs like “Left of Center” a harried urgency, as do filaments of Armenian folk, which evoke the singer’s embattled ethnic heritage. On Imperfect Harmonies, that frenetic sense of border-crossing is the clearest connection between Tankian’s beloved band and his strange new freedom.