Top Australasian violinists Dmitri Atannasov, Justine Cormack, Vesa-Matti Leppanen, Dene Olding and Wilma Smith judged 90 CDs of Paganini, Bach, and sonatas in Auckland early this month.
Ms Smith, concertmaster of the Melbourne Symphony Orchestra and former concertmaster of the New Zealand Symphony Orchestra, said aural and mental exhaustion took over during the process of whittling down 90 highly-qualified applicants.
Although the applicants were required to submit CVs, photos, letters of recommendation and DVDs to authenticate their recordings, the panel made its determinations solely on the audio recordings and did not know the identities of the applicants until the selection was completed.
Long-serving panelist Justine Cormack, of the NZTrio, said the bar was raised considerably this year.
"Each year our job gets harder."
Of the 18 semifinalists who will compete in the Queenstown competition, seven are Korean, three are American, two are Canadian and the others are British, Polish, Russian, Taiwanese, Japanese and Chinese.
They are all aged 18 to 28.
New Zealander Sarah Buchan was one of the six alternates selected.
Originally from Christchurch and recently graduated from The Juilliard School in New York, Ms Buchan was also the winner of the inaugural New Zealand Development Prize.
The prize was created to offer an intensive development opportunity for a Kiwi violinist to accompany and observe the competitions proceedings, participate in the masterclasses being offered by the international artist judges and be acknowledged in the prize-giving.
If Ms Buchan was called upon to compete in the competition, the prize would be awarded to Auckland violinist Eugene Kim.
The 2009 competition kicks off in Queenstown June 4 to 6 where the semifinalists perform demanding programmes of solo and piano-accompanied works.
The top six then perform in Auckland on June 8-9 with cellist Ashley Brown and pianist Michael Houstoun.
The three finalists advance to compete in the final round, accompanied by the Auckland Philharmonia Orchestra, in the Auckland Town Hall, on June 11.