Soprano Grace Park, baritone Kawiti Waetford and tenor Alexander Wilson, all aged 21, were among the six finalists named on Saturday.
"We're really good friends, so it's great that we're all in the final together," Mr Waetford said.
"It's the first time any of us have been in the final.
"We're the youngest finalists this year, too," Mr Wilson added.
"I thought I'd give it a go, but it was unexpected to make the final. It was a very nice surprise and it's very encouraging," Ms Park said.
The trio praised their University of Otago teachers, Isabel Cunningham, Judy Bellingham and Prof Terence Dennis.
"It's a really big testament to our teachers that the three of us are in the final," Mr Waetford said.
"It's a stepping stone if you want a professional career.
"You only have to look at all the finalists in the past who have gone on to have big careers."
Three Dunedin singers previously won the prize: Martin Snell (1993), Jonathan Lemalu (1998) and Anna Leese (2002).
The other 2012 finalists are Auckland counter tenor Stephen Diaz (24), Auckland tenor Amitai Pati (22) and New Plymouth soprano Bryony Williams (22).
Competition preliminary judge Rodney Macann said he was impressed with the calibre of this year's finalists.
"There is a beautiful multicultural mix in the group which makes them very representative of Aotearoa, New Zealand today.
There is also a strong sense of community among this group and many were curious to discover whether their friends were also successful," Mr Macann said.
"All of them, with their very individual talents, are potential Lexus Song Quest winners."
The winner will take home $25,000 in prizes, including a study scholarship and cash grant.
The final concert, with the New Zealand Symphony Orchestra, will be held at the Michael Fowler Centre in Wellington on August 30.
