NATE RUESS His latest project proves that going solo is fun, too  After nearly three years of supporting Some Nights—the platinum-selling, 2012 breakthrough album by his Grammy-winning band fun.—Nate Ruess was feeling good. So good, in fact, he opted to temporarily step away from the trio and go solo. It was a bold move for the singer-songwriter, but it’s paying off. His album, Grand Romantic—a fittingly titled set of massive-sounding earworms...