About 500 mainly young people packed into the hall for the big music event, which is organised by Music Education Otago.
''It was amazing. Everyone was rocking and rolling, they're all part of a group,'' Music Education Otago chairwoman Ruth Buchanan said.
Months of preparation by pupils and teachers in participating schools had paid off in the ''liberating'' experience of everyone singing and strumming along together, and greatly enjoying the occasion, she said.
The annual event had begun with 800 participants nine years ago. Participation had since risen to about 1000, and organisers would be looking for a bigger venue next year.
Music Education Otago had in March also organised the biggest mass ukulule performance event in Dunedin history, by offering a huge strum-along to celebrate musician Ed Sheeran's performances in the city.
The music education organisation was moving on from strength to strength.
Yesterday's performances, from 9.30am to noon, were supplemented by the use of orchestral instruments, such as trumpets, trombones, cello and flutes, for the first time, she said.
Other event organisers were Alison Caldwell and Rachel McNamara.
Another 500 pupils are expected to pack into the school hall today for the second day of the jam programme, and 44 schools in the Dunedin area would contribute pupils to the ''awesome'' two-day event, she said.
