Rihanna has unveiled her penultimate ANTIdiaRy teaser video for her forthcoming album 'Anti'. Elsewhere, Australian pop star Sia has previewed her new track Reaper, which she had originally planned to give to RiRi for the album, but ended up keeping it for her own record 'This Is Acting', which will be released later this month. The Elastic Heart hitmaker - who co-wrote Reaper with All Day rapper Kanye West - had been working with Rihanna and offered her a plethora of songs, but she's not sure if they will make the final cut.