Historical clue formulations

• N.Y.C. opera house — 2020-09-01
• Manhattan cultural landmark — 2013-04-30
• Venue where Toscanini conducted — 2012-10-30
• Lincoln Center institution — 2010-08-08
• Locale for a New York diva — 2007-12-31
• N.Y.C. opera venue — 2007-01-09
• Place where 27-Across is sung — 1999-03-13
• Aspiring diva's goal — 1999-03-05