Conor Oberst first tested out this unreleased tune last summer and fall, along with “You Are Your Mother’s Child,” on a string of solo tour dates. But Friday it arrived again, this time in more mature form for one of those show-stopping moments “Lua” usually delivers. He played that one, too, during a surprise opening set at a Felice Brothers show in Hoboken, NJ. Unexpected appearances like this are among many (such as the Replacements’ epic SNL afterparty/gig in 1986) Maxwell’s visitors have caught for over three decades, and sadly the venue’s 35-year run closes in July. Watch Conor help sing out the to-be-late, great club above.