Sia Premieres 'Cheap Thrills,' Meant Initially for Rihanna, on Beats 1

Sia's cloak-and-dagger new album This Is Acting -- all of the songs were written initially for other artists, including Adele and Beyoncé -- impacts in late January, and now the Australian singer has shared a new taste of the project, "Cheap Thrills," on Beats 1. Meant at one time for Rihanna, the song glistens with a synth-heavy skin -- it's certainly her poppiest…