Kelly Clarkson was moved to tears on stage in one of her final performances before the death of her ex-husband, Brandon Blackstock. In an emotional video from the July 26 show of her Las Vegas residency, Clarkson, 43, wiped her eyes while introducing her song "Piece by Piece." "This next song, I've never rewritten a song more," she told the audience. "And I probably never will. I wrote this song with a lot of hope, OK? And projection for happiness and [something] better than what was happening. And then, well, life set in and I had to change the lyrics.