Historical clue formulations

• Picasso masterpiece with a French title — 2016-03-18
• "___ en Rose" (song classic) — 2016-02-02
• Allegorical painting from Picasso's Blue Period — 2015-02-21
• "C'est ___" — 2011-07-17
• "___ en Rose" (Edith Piaf song) — 2010-06-01
• "C'est ___" — 1998-03-27
• "C'est ___" — 1997-05-21