ONE FLIGHT UP (LP)Again one wonders: where would jazz have gone without the advent of the LP? Certainly not down the path that brought us the 18 minute "Tanya," which originally took up the entire first side of Dexter Gordon's second expatriate album for Blue Note in 1964. Based in Copenhagen since 1962, Gordon assembled a group in Paris for this session, including fellow Americans abroad Kenny Drew, Donald Byrd and Art Taylor. It's Byrd who contributes "Tanya," a