Possible Clues:

• She played Glinda in the 1978 film version of "The Wiz"
• Siberian river to the Arctic Ocean
• Legendary performer Horne
• Headey of “Game of Thrones”
• 'Game of Thrones' actress Headey
• "Chocolat" actress Olin
• Contemporary of Ella
• Name hidden in "middle name"
• Tuneful Horne
• ___ the Hyena of 'Li'l Abner'