Graham Russell & Russell Hitchcock met on May 12, 1975, the first day of rehearsals for “Jesus Christ Superstar” in Sydney, Australia; they became instant friends with their common love for The Beatles and, of course, singing. After the shows’ performances at 10:30, they would play pizza parlors, coffee bars and night clubs with just one guitar and two voices. They quickly gained a reputation for great harmonies and for original songs that Graham was constantly writing. They made a…