The record companies behind some of Britain's biggest artists such as Radiohead and Adele have warned that Brexit would be "disastrous".
Universal Music and Beggars Group, which together represent the likes of Sir Paul McCartney and Dizzee Rascal, have written to staff and the "wider music community" to urge them to vote Remain in Thursday's poll.
In a joint letter, they said staying in the European Union is strongly in the interests of the companies and artists.
Universal chief executive David Joseph and Beggars founder Martin Mills wrote: "First and foremost we are writing to urge you to vote on Thursday, but also to consider all of the issues carefully. We believe a victory for Brexit would be economically, politically, socially and culturally disastrous - for all of us.
"Many of you will be travelling to Glastonbury on Thursday, the day of the vote. To us, Glastonbury embodies the inclusiveness that a Brexit vote seeks to reject.
"No-one thinks the EU is perfect. It's undeniably flawed. But when your family is imperfect, you don't abandon it - you stay with it, and seek to make it better. That's what we need to do here."
With hours to go before polling opens, a ComRes poll for ITV News suggests nearly one in five voters haven't decided which way they'll vote.
Gary Lineker received a torrent of abuse on Twitter after revealing he is backing Remain in the EU referendum.
Michael Gove has apologised for his "clumsy" comments comparing EU referendum experts to Nazis.