“Vengeance is mine; I will repay, sayeth the Lord.” Taking his cue from those thunderous words, the young Sergei Rachmaninov launched into the mother of all First Symphonies: huge, dark, and blazing with unrequited emotion. It’s a real gothic melodrama – so the CBSO is beginning with something very different: Tchaikovsky’s musical postcard from Italy and the world’s favourite violin concerto, played by superstar soloist Ray Chen.