Spherical Harmonics is an experimental composition process and collaboration between conductor Majella Clarke and composer Peter J. Østergaard. The instrumentation is unique with a sonic conducting baton, electric guitar and modular synthesiser. The scoring for the conductor gestures is based on spherical harmonics - while used extensively in various fields such as physics, engineering, and computer graphics to solve problems involving spherical domains, this artistic process uses spherical harmonics to generate a series of gesture scores. The conductor traces the gesture score of the spherical harmonics with their baton. The gesture movements are synthesised in Max and provide a sonic accompaniment to the electric guitar.