Genera Esfera is an interactive installation that allows the audience to interact and easily become a VJ (visual DJ) in a world of generative visuals. It is an animated and generative graphic environment with a music playlist, a visual spherical world related with and suggested by the music, which reacts and evolves. The installation has been presented at MIRA Live Visual Arts Festival 2015, in Barcelona. Genera Esfera was envisioned, developed and programmed on the basis of two initial ideas: first, to generate our spherical planets we need to work with spherical geometry and program 3D graphics; second, the interaction should be easy to understand, proposing a direct mapping between the visuals and the interface. Our main goal is that participants can focus on exploring the graphic worlds rather than concentrate on understanding the interface. For that purpose we use a trackball to map its position onto sphere rotations. In this paper, we present the interactive installation Genera Esfera, the design guidelines, the mathematics behind the generative visuals and its results.