Chainsmokers & Kelsea Ballerini

The Chainsmokers are an American DJ and production duo consisting of Alex Pall and Andrew Taggart. The EDM-pop duo achieved a breakthrough with their 2014 song "#Selfie", which was a top twenty single in several countries. Their debut EP, Bouquet was released in October 2015 and featured the single "Roses", which reached the top 10 on the US Billboard Hot 100. "Don't Let Me Down" became their first top 5 single there and won the Grammy Award for Best Dance Recording at the 59th awards ceremony, while "Closer" became their first number-one single on the chart. They have also won two American Music Awards, seven Billboard Music Awards and eight iHeartRadio Music Awards.
The duo's second EP Collage was released in November 2016, succeeded by the release of their debut studio album, Memories...Do Not Open, in April 2017.

Kelsea Nicole Ballerini (born September 12, 1993) is an American country pop singer and songwriter. She is signed to Black River Entertainment, and released her first album The First Time in 2015. Her second album Unapologetically was released on November 3, 2017. She received a nomination for Best New Artist at the 2017 Grammy Awards.
Ballerini's two albums have accounted for seven charted songs on the Hot Country Songs and Country Airplay charts. She has four No. 1 singles on the latter, starting with her debut single "Love Me Like You Mean It", which made her the first female artist to send a debut single to the top of that chart since Carrie Underwood did so in 2006. It was followed by "Dibs" and "Peter Pan", whose peaks also made her the first female country artist to send her first three singles to the top of that chart since Wynonna Judd. Ballerini's fourth No. 1 single is "Legends."