The Cavendish Beach Music Festival is adding some pop to its country lineup — multi-platinum selling international superstar Shawn Mendes will headline a fourth night, extending the concert weekend through Monday, July 9. 

Toronto-born Mendes is only 20 but already has two mega-hit singles, Stitches and Treat You Better, and has headlined three of his own world tours. 

CBMF also announced 17 more artists for the four-day festival, including Chris Young, Brett Eldredge, Terri Clark, The Road Hammers, Meghan Patrick, Petric, James Barker Band, Law, Cashmere Cat, Broods and more. 

The organizers also announced what they called "a new major partnership" with Bell Canada over the next three years.

CBMF three-day passes are on sale now. Single-day passes and four-day passes and will be on sale this Friday.