If it’s true that practice makes perfect, then Graham Russell and Russell Hitchcock–beloved by their millions of fans across the planet as Air Supply–have had nearly half a century to hone their skills, harness their passion and unleash the beautifully intimate yet rockin’ romantic energy of those instantly identifiable 80s hits that made them global superstars. As they close in on 50 years (exact date, May 12, 1975) since they met in the chorus of the Australian touring company of Jesus Christ Superstar, the duo is ever-present on the road in North America and overseas to the tune of 130 …