In 2015 and 2016, what country held a series of referendums to potentially select a new flag, with the leading candidate featuring a silver fern representing the multi-cultural people of the country, in front of a black and blue background?

In 2019, YouTube released the list of the most-viewed music videos by decade of release. Of the music videos released in the 1980s and 1990s that reached the top ten for either of those decades, three are songs credited to solo women. Name 1 of those 3.