Like mushrooms after rain, vinyl copies of Boz Scaggs’ Silk Degrees tend to sprout up overnight in people’s record collections. “Jeez, I don’t remember buying this,” every record collector has said at one time or another, suspiciously eyeing the iconic album cover with Scaggs on a park bench looking either drunk or dejected as a manicured lady hand suggestively reaches into frame. The former Steve Miller Band guitarist’s blockbuster 1976 album is a swankfest from bygone days, a surprisingly ambidextrous collision of string-laden R&B, gently discofied beats, singer/songwriter introspection, and Springsteen-esque bar-band bravado. And its two hit singles couldn’t be more different: “Lowdown” was, probably, sexy for its time, with its Barry White groove and burning-cool jazz flute; nowadays it sounds immeasurably creepy. But “Lido Shuffle” has a McCartney-worthy melody, a Thin Lizzy quick-shuffle rock beat, and the soaring sing-along chorus of your karaoke dreams. Scaggs has apparently recorded dozens of other albums that you’ve never heard, and presumably he’ll play songs from some of them tonight, but expect those Silk Degrees jams to be the meat of the set list. NED LANNAMANN