Historical clue formulations

• Catchphrase for Captain Underpants — 2024-11-13
• Nonsensical song syllables — 2022-02-26
• A chorus line? — 2018-11-16
• Refrain from singing? — 2017-05-31
• Skipping sounds — 2016-09-24
• Joyful refrain — 2015-06-03
• Refrain syllables — 2014-07-16
• "I haven't a care in the world" — 2011-03-18
• Light refrain — 2010-04-14
• Refrain from singing? — 2008-10-23
• Syllables to skip by — 2007-11-17
• "An American in Paris" song — 2007-05-18
• "An American in Paris" song — 2006-10-28
• Sounds of gaiety — 2003-10-04
• Refrain from singing? — 2002-10-01
• Happy-go-lucky syllables — 2002-05-13
• Skipping syllables — 1999-04-10
• Singsong sounds — 1997-06-06
• Vocal filler — 1995-10-27