Possible Clues:

• "My Best Girl" musical
• Musical title aunt
• Classic musical with the song 'If He Walked Into My Life'
• “We Need a Little Christmas” musical
• Musical Auntie played by Angela Lansbury
• It lost the Best Musical Tony to 'Man of La Mancha'
• 1966 Broadway role for Angela Lansbury
• Jane Russell's version of 10
• Musical title character who 'made us feel alive again'
• 1966 Broadway musical