Historical clue formulations

• Neapolitan song whose first line translates to "What a beautiful thing is a sunny day!" — 2020-06-19
• Pavarotti standard whose name means "My Sunshine" — 2018-03-30
• Song whose opening lyric translates to "What a beautiful thing is a sunny day" — 2017-05-05
• Song for which 17-Across won a Grammy — 2015-09-25
• Common number of gondoliers — 2013-06-28
• Basis of the song "It's Now or Never" — 2013-01-05
• Basis of Tony Martin's "There's No Tomorrow" — 2009-07-03
• Song that Elvis's "It's Now or Never" was based on — 2007-09-09
• Source for the tune of "It's Now or Never" — 2005-08-27
• Popular tune for tenor or accordion — 2002-06-16
• Pavarotti standard — 2002-01-04
• Mario Lanza favorite — 2001-04-11
• 1899 Eduardo di Capua melody — 1999-01-28
• Pavarotti encore — 1995-11-05