Ever since Deep Throat was outed in 2005, D.C. has been lacking one of its greatest emblems—the District (at least the feds’ version of it) thrives on the notion that this is a town full of mystery, shady doings, and singular personages who keep the engines of government moving well away from the headlines. Such folks certainly still abound here, but they’re doing a better job with their covers, so Mingering Mike is the best symbol of obscurity we’ve got. In the late ’60s and early ’70s, the local outsider artist made himself the star of dozens of imaginary soul albums, many of them D.C. tributes. (One album was “recorded” at the Howard Theater; others came out on Nation’s Capital records.) Since his faux records were discovered at a flea market in 2003 by Dori Hadar and Frank Beylotte, Mingering Mike has become something of a District phenom, earning a well-received exhibition at Hemphill last year and featured in a book collecting his works. Who is he? Anybody who knows for sure isn’t telling, but perhaps that’s as it should be.