Who played Ken in 'Barbie' (2023)?

Which singer played Ally in 'A Star Is Born' (2018)? Who played Elvis Presley in Baz Luhrmann's 'Elvis' (2022)? Who played Paul Atreides in 'Dune' (2021)? Who played Barbie in 'Barbie' (2023)? Who played Sebastian in 'La La Land'? Who played Andrew in 'Whiplash' (2014)? Which actor won an Oscar for playing the music teacher in 'Whiplash'? In 'The Social Network', which actor plays Mark Zuckerberg?