The soft pop duo Air Supply _ Australian Russell Hitchcock and Englishman Graham Russell _ are marking a quarter century together. Best known for 1980s hits such as Lost in Love, All Out of Love, Every Woman in the World, Just Another Woman and The One That You Love, the two are touring in support of their 17th album, The Book of Love. They perform tonight at 8 at the Mahaffey Theater in St. Petersburg. Tickets are $29-$35. Call (727) 892-5767.