Sunderland looks to have claimed a new world record with a mass singalong as part of the Tall Ships Races events programme.
Thousands of children in the city joined others at schools nationwide in a mass singalong organised by Sunderland Music Hub and NYMAZ.
Early indications are more than 5,000 children were involved in the city, and the world record record for singing has fallen.
More than 700 children performed on stage at St Peter's in events zone C at the Tall Ships, with 1,400 on stage in the Sunderland Empire and thousands more at schools across the city.
They were joined by many more live streaming from classrooms around the country.
Rebecca Pedlow, manager at the Sunderland Music Education Hub which is run by Together for Children, said: "Looking at the early figures, it looks like we've achieved the world record."
She added: "If you teach children to play a musical instrument and engage them that's great, but it's better if you can give them something to aim for. Like a footballer with a match to play in."
Schools taking part were asked to learn three songs; Jack He Was a Sunderland Lad - about Sunderland's Jack Crawford, the hero of Camperdown who nailed the colours to the mast, Three Little Birds and Heroes, We Could Be.
Many other songs were sung, however, including he apt We Are Sailing.
Simon Marshall, director of education at Together for Children, said the Big Sing had been a tremendous achievement and praised everyone involved.
"This is the culmination of a lot of hard work right throughout the year," he said.