In his early years, Sainsbury was involved in various regional and community musical groups during the 1960s and 1970s which have become important influences in his work.
[1] In 1984, Sainsbury studied composition under Australian conductor and composer Richard Mills.
He began teaching music at the Eora College in 1990 where he was the Head of Arts and Media until 2015.
Sainsbury has made significant contributions to elevating Australian First Nations voices and representation in music.
He describes himself as "a regionalist composer" as a way to acknowledge his regional upbringing as his most important influence on his music.