Joseph Ongenae met Jan Cox during the Second World War, who taught him painting. Following Kandinsky's theories, he made as theosopher his first abstract works. After the War, when he moved to Amsterdam, he became inspired by Mondriaan and made fully abstract works, following the strict rules of horizontal and vertical lines.
After 1955, his work consisted only of colored squares, triangles and rectangles, set on a monochrome backdrop. Compositions were made following the analogies of music such as Jazz, Bepop and Indian music.