The review of Swedish Concerts in the SvD by Carl-Gunnar Åhlén said:
“And seldom have I felt so secure with high tenor notes as when the Australian Sweden-debutant D. N. sang Verdi & Puccini. But then again - his wonderful  voice rests upon an earlier life as a baritone.”

Review of Macbeth Concertante in Concertgebouw in Amsterdam:
“Verdi gave him (Macduff) the most beautiful aria of the opera. It was sung with a miraculous voice of beauty by D. N.”
“The baritone, the young bass, and the tenor D. N. brought from their origins authentic Italian phrasing together with their beautiful voices.”