St George's Chapel's lofty heights normally reverberate to traditional choral music but the Kingdom Choir, directed by its founder Karen Gibson, is expected to put on an inspirational performance.
The gospel choices are likely to be down to Meghan Markle, who appears to have brought the sounds of her American homeland to the Gothic chapel.
Ms Gibson, who will lead her group during the service, has said: "The Kingdom Choir is truly honoured to be invited to sing at the wedding of Prince Harry and Ms Markle, and very excited to be taking part in such a historic moment.
"It will be a moment that we will always treasure and we'd like to take the opportunity to wish the couple all the very best for their coming union."
After the US bishop Michael Curry gives the address, the gospel choir will perform Stand By Me, made famous by singer Ben E King but also sung by Beatle John Lennon.
When the bride and groom walk through the chapel after they are married, the gospel choir, who will be positioned at the west end of the place of worship, will sing the gospel classic Amen/This Little Light of Mine.
It is a favourite in African-American churches across the US and versions of the song have been sung by a string of soul artists from Otis Redding to Sam Cooke, but they will perform Etta James's version.
The newlyweds will begin their journey along the aisle with a contrasting piece of music from 18th-century English composer William Boyce, his symphony no.1 in B-flat, which has a triumphant celebratory tone.
Other highlights from the music chosen by Harry and Meghan include the song which is affectionately known as the Welsh rugby hymn - Bread of Heaven - or Guide Me, O Thou Great Redeemer.
Harry will have joined the crowds at Cardiff's Millennium Stadium in singing the song during Welsh international rugby matches and it was also chosen by the Duke and Duchess of Cambridge for their wedding.
When picking the music due to be played before the service begins, the couple asked the Prince of Wales - who will walk the bride down the aisle - for help in making the selection.
It features one of Charles's favourite composers Sir Hubert Parry, a figure the prince made a documentary about, and works by Sir Edward Elgar, Vaughan Williams, Gustav Holst and Johann Sebastian Bach.
As the bride and groom sign the register, teenage cellist Sheku Kanneh-Mason, a rising star of the classical music world, will perform three pieces - by Faure, Schubert and Maria Theresia von Paradis, with the Orchestra - musicians from the BBC National Orchestra of Wales, the English Chamber Orchestra and the Philharmonia.
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