The year 2025 puts us one quarter of the way through the 21st century. We'll spend the year looking back at some of the amazing advances we've experienced. In this episode: privatized space travel.

On today's (Oct. 30) episode of the Greatest Pop Stars of the 21st Century podcast ... with her public breakdown being used as cheap fodder for insulting headlines and bad late-night punchlines.

By Andrew Unterberger With the first quarter of the 21st century coming to a close, Billboard has spent the last few months counting down our staff picks for the 25 greatest pop stars of the last ...