Youngsters from all over the UK gathered to help rewrite the famous Blue Peter TV theme.
The youngsters were chosen from more than 26,000
They joined the BBC Philharmonic Orchestra in Manchester on Sunday to create a new version of the tune, called Barnacle Bill.
It followed a search for 40 children, aged seven to 15, who earned the honour of playing alongside the orchestra.
Gethin Jones, one of the Blue Peter presenters joining in the recording, described the new version as "jazzy".
He added: "Some of the children are brilliant musically; some had never picked up an instrument in their lives before the residential camp.
"So we have a really unique mix of music makers who will be hearing their theme tune on every Blue Peter from September onwards."
He described the theme tune, introduced in 1958, as "iconic".
"The reason this one is so special is because it is the viewers who have chosen it," he said. "It's slightly different rhythmically.
"The children wanted something a bit more jazzy and more upbeat, and that's exactly what's we've got here today."
The youngsters were chosen from more than 26,000 who completed the online entry form at the start.