In 1996, the Backstreet Boys released their debut album, "Backstreet's Back." "Millennium," "Black & Blue," "Never Gone," "Unbreakable" and "This Is Us" followed. After parting with the group years ago, Kevin Richardson (second from left) rejoined A.J. McLean, Howie Dorough, Nick Carter and Brian Littrell. In March 2017, <a href="http://www.cnn.com/2017/03/02/entertainment/backstreet-boys-las-vegas-residency/index.html">they kicked off a limited Vegas residency </a>and they <a href="https://www.cnn.com/2018/05/17/entertainment/backstreet-boys/index.html" target="_blank">released a new single in May. </a>