As musicologist and artistic researcher in the docARTES PhD program (Leiden University / Orpheus Institute, Ghent) I am focussing on (un)known possibilities of overtone singing in a choral setting. In the first phase of my research I made an inventarisation of traditions employing such techniques (in Tibet, Sardinia, South Africa and contemporary music). These activities have shifted more and more towards actually writing short exercises and compositions that should help singers, composers, theoreticians and others to become conscious in a structured way of the wealth of possibilities of overtone singing. With my group Parafonia we are showing that overtone singing is not a musical genre, but a technique with many possible applications. In the current and last phase of research I am preparing a number of CDs that document the research process and lay out a large number of possibilities that we tried out, and we are organising some concerts to present our first CD Sphere . The thesis I am writing will not only deal with overtone singing per se. This very obscure theme leads me to much broader questions about illusion and reality in the arts, science, philosophy and religion.