AFTER A DECADE and a half as one of the area’s most polished lounge singers, Lance Diamond is uncovering a new facet of his career, thanks to a scruffy rock band young enough to be his kids. The group in question is the Goo Goo Dolls, the enfants terribles of the alternative rock scene here. Diamond’s life hasn’t been the same since they brought him in for their remake of Creedence Clearwater Revival’s “Down on the Corner” for their “Jed” album, released last spring on Metal Blade Records.Finding the neatly-pressed Diamond and the shaggy Goo Goos under the same roof seems improbable, but that’