At seven years old Du Plessis began his piano studies while at school in Porterville, where he already tried to write his own music. In 1940 he started his studies at Stellenbosch University. From 1941 English and Music were his main subjects. At the Stellenbosse Conservatory prof. M. Fismer and Alan Graham had a big influence on him. One year later started composing lessons with prof. W.H. Bell. In 1942 he was the first person to receive the grade B.Mus at Stellenbosch University (with honor). On 12 Maart 2011 he died, aged 88, in his house in Stellenbosch.