Loudon Wainwright III, the singer-songwriter still known best for his sole charting single, 1972’s “Dead Skunk,” despite having written and recorded dozens of better songs, calls this collection his “audiobiography.” For the release, Wainwright went into his personal archives—so far back that his birth certificate is among the treasures pictured in the accompanying hardcover—and dug out 42 home recordings, live cuts and other previously unreleased tracks. It’s all over the place, to be sure, but Wainwright is an organized kind of fellow so the two discs are divvied up into seven thematic sections, among them songs for (or from) kids, love songs, folk, rock and more. Don’t like one type of song? Move along then. But you won’t want to because there are little gems tucked in throughout, from the homey 1974 duet on Dylan’s “You Ain’t Goin’ Nowhere” with then wife Kate McGarrigle to a birthday poem from Wainwright’s three young kids, each now a popular artist in his/her own right. Some of the tunes stretch back decades, like the cover of “Smokey Joe’s Cafe” recorded at My Father’s Place on Long Island in 1977; others are more recent, including 2014’s “It Ain’t Gaza,” which concludes that it just ain’t. Most fall somewhere in between and there are plenty of surprises that’ll please longtime acolytes (“Your Mother & I,” with Bill Frisell on guitar), even if they won’t win over those still stuck in “Skunk”-ville when it comes to LWIII.