Historical clue formulations

• Jingle, e.g. — 2018-10-31
• Jingle, e.g. — 2015-08-09
• Jingle, e.g. — 2013-01-19
• "Mary Had a Little Lamb," e.g. — 2009-11-18
• Little jingle — 2006-02-17
• Simple song — 2005-04-04