Students from Eastergate, Westergate and Tangmere are the first in a series of schools to sing for the royal baby.
The group of 114 pupils came together on Wednesday at Ormiston Six Villages Academy in Westergate to perform and record their song Walk With Us.
Once completed their song which will be played to new prince, Archie Harrison Mountbatten Windsor.
Singer, song writer Emily Barden and Ken Burton, who appears regularly on BBC1 Songs Of Praise, wrote lyrics thanks to the help of students from across Sussex who sent in their suggestions.
“It’s a musical gift from the community of Sussex, West Sussex Music, and Ken to this newborn baby. We’re saying here is our land, come share it with us.
“Ken had an idea and got in touch with West Sussex music. They then got in touch with me.
“Ken and I contacted each other and West Sussex music sent out an email across Sussex.
“I sorted through everyone’s ideas and got it together into one form. We wrote the song one afternoon in front of the piano at my house. Ken then went away and produced the track sound.
Ken said: “The track is an accumulation of different sounds from across Sussex and the UK. “We’re representing the different cultures in the UK, kind of like how Harry and Meghan are, too.”
The Year 7 and 8 Ormiston students were joined by Year 6 pupils from Eastergate Primary School and Tangmere Primary Academy.
Year 8 students Hollie Glasspool and Farrin Maleki-Raee were among the Ormiston pupils.
“I have always loved singing. I do choirs outside of school and I have already done some stuff with Emily before when she was a judge on a competition I took part in. I’m in a choir called Little Lyrics. Today has been great just getting to sing with my friends.”
“We did singing last year with Emily,” Farrin said, “and I really enjoyed that”
“I wanted to do that again. The recording part was great because we finally came together. It’s amazing that people are going to hear it and it’s great we take part in it.”
Ellie Thorn and Tempo Nosivu, from Tangmere Primary Academy, both in Year 6, went to the school for the day to join in.
“I wasn’t 100 per cent sure about doing it at the start, but it has been really fun. Being with my friends is nice. It’s amazing that we get to sing for Archie and that lots of people are going to hear the song.”
Emily and Ken hope to have the song completed and ready for release by Christmas.