The Beatles legend was "touched and honoured" by the request
The cast is filling up ahead of the films' 2028 release
She will star opposite Paul Mescal's take on Macca in the four-part film series
"I think he'd fallen out of love with a certain kind of fame"
The US leg of Macca's 'Got Back' tour kicks off in Palm Desert, California this week
"I will genuinely never forget putting the cassette in… I never heard anything like it"
The Oscar winner also talked about his love of Radiohead
Both musicians appeared on the line-up for the US festival
The couple went public on Instagram in July
The two stars have made three films together in the last four years