Taylor Swift must be a big fan of Echosmith.
Swift Approval: Taylor Swift's Favorite Covers of Her Songs
For the latest guest artist on her widely successful 1989 tour, Swift brought out the sibling rock band's lead singer Sydney Sierota to perform their breakthrough hit “Cool Kids.” This marked the second occasion Swift has performed “Cool Kids” with Echosmith in concert. In June, the band joined her on stage in Philadelphia.