About 70 past and present orchestra members were in Dunedin to attend the reunion, including watching or taking part in Saturday night’s Gallipoli to the Somme performance at the town hall.
They also enjoyed lunch together and spent the afternoon swapping stories about the orchestra’s history, DSO marketing manager Pieter du Plessis said.
Members travelled from around New Zealand for the reunion.
The longest-serving member taking part was Dunedin-based violinist Patricia Leen, who had been with the orchestra since its formation in February 1966, Mr du Plessis said.
Dunedin composer Anthony Ritchie said the standing ovation for the world premiere of his composition Gallipoli to the Somme was "very moving".
London-based Simon Over, in his second year as the orchestra’s principal guest conductor, will conduct the Southbank Sinfonia and Parliament Choir in London in 2018 when Prof Ritchie’s composition will have its UK premiere.