Does “Perfect World” measure up to “Can You Fly”? It’d take an electron microscope to figure out which is the better album. Johnston’s best songs reveal their true intentions slowly. Listen once to the title track of “Perfect World” and you hear a gorgeous, trembling song about a young father mourning the loss of his wife. Listen again, and you realize he’s murdered her and dumped her body in a lake. The album moves from sorrowful acoustic ballads to upbeat rockers. Improbable as it seems, it was produced by Butch Vig, whom Nirvana made famous, or vice versa. Vig works in a cello here and there and some wiry, melodic guitar work from Marc Ribot and Dave Schramm. But he has the good sense to err on the side of simplicity. This singer’s songs don’t need much help, as we first learned a few years back when he made the best decision of his life. Someone got a farm in Kinsley, Kans., but we got Freedy Johnston.