Spooky, amusing, and weirdly moving, "Paved Paradise: The Songs of Joni Mitchell" is either the gentlest sendup or the sharpest hommage you'll ever see. Performance artist John Kelly doesn't so much impersonate Mitchell as channel her, and he does it with a blend of affection and discernment that is remarkable to behold.
A few audience members at the Boston Center for the Arts, where the Theater Offensive is presenting Kelly's show this weekend as part of its Out on the Edge Festival, may go in expecting your basic drag act. At first Kelly plays to that expectation - he's wearing a wig and a dress, after all, and he exaggerates the mannerisms of his subject (the prayerful hands, the rubbery grin) with the fond mockery you'd expect from a guy who honed this act at Wigstock in the fabulous 1980s.