Historical clue formulations

• All-vowel musical refrain — 2026-08-30
• Letters before "And on that farm ..." — 2025-11-17
• Nursery song refrain — 2025-09-17
• Children's song refrain ("Old MacDonald had a farm …") — 2025-07-28
• Farmyard refrain in a children's song — 2025-07-15
• Refrain in 51-Across that accompanies the sounds at 24-, 37- and 47-Across — 2022-11-15
• Apt vowels missing from this phrase: TH_ L_TTL_ K_DS' S_NG — 2022-10-03
• MacDonald's jingle? — 2022-02-09
• Letters heard after "cow," "pig" and "horse" — 2021-11-16
• Farm refrain — 2021-09-12
• Follower of pigs or cows — 2021-01-28
• Refrain in a children's song ... or a literal feature of 17-, 25-, 42- and 55-Across — 2020-08-11
• Children's song refrain — 2020-04-05
• Refrain from nursery singing — 2020-01-19
• Letters from down on the farm? — 2019-10-16
• Mi-mi-re-re-do, in a children's song — 2019-06-04
• Farm refrain — 2019-02-28
• "Old MacDonald" refrain — 2019-01-22
• Letters sung as mi, mi, re, re, do — 2018-07-06
• What might come after a cow or a sheep? — 2018-06-02
• Farm refrain — 2018-01-21
• Trailer for farm animals? — 2016-12-10
• Children's song refrain found at the starts of 17-, 26-, 35-, 50- and 57-Across — 2016-05-31
• Letters associated with animal sounds — 2015-10-03
• Noted preschool sequence? — 2015-01-10
• What goes after cows, ducks and pigs? — 2014-08-16
• Farm refrain — 2014-07-06
• Letters in a children's refrain — 2014-04-02
• "Old MacDonald" refrain — 2013-12-23
• Farm letters? — 2013-10-08
• Children's song refrain — 2012-11-14
• Sequence sung by kids — 2011-12-14
• Kids' song refrain — 2011-06-28
• Children's song refrain — 2011-02-20
• Farm letters? — 2010-03-16
• Children's song refrain — 2010-01-20
• Letters after many animal names — 2009-12-26
• Kid's song refrain — 2008-12-10
• Children's refrain — 2008-06-11
• Farm letters? — 2007-08-02
• Nonsensical refrain — 2006-11-04
• Follower of ducks, sheep or pigs — 2006-10-28
• Old MacDonald refrain — 2006-07-03
• Farm letters? — 2005-12-01
• Children's refrain — 2005-11-02
• Children's song refrain — 2005-10-25
• Follower of cow, pig or horse — 2005-09-08
• Farmer's letters? — 2005-03-02
• Follower of a duck, pig or cow — 2005-02-26
• Sequence sung by kids — 2005-02-05