Historical clue formulations

• The Swedish Nightingale — 2014-09-21
• Jenny ___ a k a the Swedish Nightingale — 2011-01-23
• Swedish soprano Jenny — 2007-11-12
• Operatic Jenny — 2007-04-22
• Soprano Jenny — 2004-09-18
• Swedish diva Jenny — 2003-11-03
• Soprano who once worked for P. T. Barnum — 2002-07-28
• The Swedish Nightingale — 2000-03-24
• Star of an 1850's Barnum tour — 1996-08-09
• Barnum's soprano — 1994-02-24