Video: Jay-Z’s Subway Surprise, Mariah’s Holiday High Note, and More Viral Hits!

Get excited – Friday has arrived! It’s time to review the week in celebrity viral videos! Jay-Z charms a subway-riding senior, John Travolta and Olivia Newton-John have a hilarious holiday reunion, Mariah Carey and Jimmy Fallon go Kindergarten on her Christmas classic, and more in today’s addictive PopSugar Rush.