Yall are too much, making everything a stan war. Sia knows what it is and if she didn't like the experience working with Rihanna she wouldn't continue to write/work with her cause she is established (like Dianne Warren) and many artist would die to work with her. Also how do you know Rihanna is even aware that there is a session going on her team of of called and cohoaxed Sia to a session and not told Rih about it hence her not showing up. And death at people saying Rihanna isn't a real artist when most of your faves don't do shit. Rihanna may not write her songs ( even though she's co wrote on a handful) but she def is in charge of her image. Hell even Whitney and Celine didn't write their own songs or control their image into late into their careers, in fact most of Celine's hits were covers of other people's hit songs. Britney didn't write her own songs, the list goes on.