Their 21-page order of service reveals that – as well as traditional hymns, prayers and readings – the ceremony will include contemporary wording and songs.
In her vows, Meghan will also not make the promise to obey her husband and will walk part of the way down the aisle by herself.
In a nod to her American roots, Stand By Me, by American soul singer Ben E King, will be performed by gospel group The Kingdom Choir.
As the newlyweds leave St George’s, the choir will perform Etta James’s version of Amen/This Little Light Of Mine, which is a favourite in African-American churches.
With the Queen being head of the Church of England, the ceremony is still very religious. However, it will use words from the more up-to-date marriage service from common worship.
It uses language such as “you” – instead of “thee” or “thou”.
The American former actress and the prince will pledge themselves to one another using the familiar: “for better, for worse, for richer, for poorer, in sickness and in health, to love and to cherish, till death us do part”.
The Archbishop of Canterbury, who is leading the service, will ask the 600 guests: “Will you, the families and friends of Harry and Meghan, support and uphold them in their marriage now and in the years to come?”
The guests will answer: “We will.”
At the start of the service, he will refer to the bride as Rachel Meghan, her given names, but will thereafter call her Meghan.
Most of the traditional hymns the couple have chosen will be well known to British wedding congregations and to those who sang hymns at school.
Rugby fan Harry is most likely to have chosen hymn and Welsh rugby anthem Guide Me, O Thou Great Redeemer, which is otherwise known as Bread of Heaven thanks to the end of the first verse.
With the lengthy order of service having been printed some days ago, Meghan’s father’s name still appears, saying he will escort his daughter through the Quire – the section of the chapel just before the altar.
There was not enough time to reprint the 600 copies because it was only on Thursday that Meghan announced he would not be walking her down the aisle.
Her soon-to-be father-in-law Prince Charles will now perform the duty.
In honour of Prince Harry’s mother, Princess Diana’s sister, Lady Jane Fellowes, will deliver a reading from the Song of Solomon.
The couple were insistent that Diana’s family played a role.
Kensington Palace said the couple thought carefully about the music, hymns and other parts of the ceremony, and had asked Prince Charles for help.
“Like any couple getting married, Prince Harry and Ms Markle have taken a great deal of care in selecting all elements for their service,” the palace said.
“This has been a collaborative effort led by Prince Harry and Ms Markle.
“They have also sought the advice of the Prince of Wales for the orchestral music before the service begins.”
Music before the service will begin at 10.35am and will include Ralph Vaughan Williams’ Fantasia on Greensleves and Elgar’s Chanson de Matin.
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The National Anthem – which is not sung by the Queen – will round off the service in keeping with royal wedding tradition.
:: Sky News is broadcasting live from Windsor with all the build-up to the royal wedding, with exclusive live coverage of the wedding in UHD in a special programme from 9am to 3pm on Sky News and Sky One on Saturday.