Historical clue formulations

• They may come with bows and whistles — 2021-05-05
• Stage comebacks? — 2019-09-02
• Concert bonuses — 2018-08-20
• Added numbers — 2018-02-18
• Performance extras — 2015-01-21
• Added numbers — 2004-07-31
• Clappers may prompt them — 2001-03-09
• 55-Across has played many of these — 2000-07-21
• Showstoppers? — 1998-06-28
• Concert extenders — 1998-04-21
• They follow standing ovations — 1997-09-16
• Showstoppers? — 1996-03-16
• Concert conclusions — 1994-11-25