The third component of the competition - the Maori Song contest - has attracted 19 singers.
There will also be regional prizes for singers from Bay of Plenty and Waikato centres.
The impressive entry list in the under-21 section confirm the competition is "growing, and not dying", said organiser Jo-Anne La Grouw.
"These are the young singers of the future who will one day enter the main aria section so the competition was in good hands," she said.
"It confirmed the event is still considered one of the most prestigious classical singing contests in Australasia."
Ten singers from the main aria contest will be selected to perform at the finals on the last night of the event, vying for the $15,000 first prize.
Three finalists from the Maori Song contest will also perform on the Sunday night.
Each finalist will be accompanied by the Auckland Philharmonic Orchestra, under the direction of conductor Tom Woods.
The 50-strong orchestra will be joined by the Chapman Tripp Opera Chorus for workshops through the weekend, and will perform on Sunday night.
"Being backed by a full orchestra can be overwhelming for some singers, but it can also help to lift their performance," Mrs La Grouw said.
Judges this year are Sydney tenor Graham Pushee, and mezzo soprano Bernadette Cullen, formerly of Brisbane.
Tickets for the finals can be obtained from Ticketmaster. Prices are: adults $55, students $40, senior citizens $40, and supper $20.