They join previously announced acts Coldplay, Damon Albarn, Haim, Idles, Jorja Smith, Kano, Michael Kiwanuka, Wolf Alice and DJ Honey Dijon.
Festival organiser Michael Eavis, 85, will lead a spoken-word narration of the five-hour event with the help of Harvey and Cocker, plus Kate Tempest, George The Poet and Kurupt FM.
Organisers also revealed timings for the show, with Wolf Alice starting proceedings at 7pm, followed by Kiwanuka, Ezra and Haim.
Coldplay will perform at 9.05pm before Blur frontman Damon Albarn and Jorja Smith.
George Ezra on the Pyramid Stage at Glastonbury in 2019 (Aaron Chown/PA)
A special unannounced guest will take to the stage at 11.05pm before grime star Kano then DJ Honey Dijon featuring Murphy.