Nisbett always loved music and, as a child, performed small concerts at home with her sister, as well as at her local Church of England.
While still working full-time, as well as studying, she was understudying the lead role of Gilda in Rigoletto, which was being performed at Melbourne's Princess Theatre.
This was a great success, receiving the first of many standing ovations and immediately establishing her as a new "star" of the operatic stage.. Nisbett continued studying (her singing teacher during that time was Pauline Bindley, a famous operatic soprano of the bel canto style) and entered many of the biggest singing competitions in Australia, including Geelong, Ballarat and the Mobil Quest.
Conductor and (future) TV producer Hector Crawford created the famous Mobil Quest in 1949 and it seems unlikely that any other country in the world had, at the time, the same sort of serious singing competition on radio solely concerned with "bringing to the attention of the public the best vocal talent available in the Commonwealth", and requiring each competitor to sing an operatic aria.
Nisbett's previous experience as a typist enabled her to continue singing lessons, while auditioning for opera companies.
The group of expat singers and musicians with whom she was friendly included Richard Bonynge, Joan Sutherland and June Bronhill.
Nisbett was in great demand by a number of opera companies; she sang full-time with London's Sadlers Wells for 8 years as one of their leading ladies.
[5] In 1965 she was approached by the Australian Broadcasting Corporation (ABC) to perform a series of operas for TV, with the Melbourne Symphony Orchestra.
She performed the role of Maria in The Sound of Music touring Australia for 15 months, including at the Sydney Opera House.
During this time she also performed at Music for the People, a very popular concert series presented by the Government of Victoria and Melbourne City Council.