Gestural interaction in live coding performance is still in its infancy, albeit the long tradition in music performance studies. Computational challenges in musical live coding have been motivating the research community towards the development of novel programming languages and interfaces. On the other hand, given the maturity of many music systems there is an increasing demand for theory building on live coding systems and practices. Here, we present an observational study from videos of live performances available online and we introduce an analytical framework for live coding music systems. We begin by examining how performance practices differ on potentially equivalent systems. On the spotlight of the framework is the viewpoint of gestural interactions under the prism of music psychology and perception. We examined several systems on three main processes: (i) interface design, (ii) gestural mapping and (iii) user's interaction. These processes are presented as an orthogonal three-dimensional framework, so to facilitate visualizations and readers' understanding. Preliminary assessments of the systems in question agree with ground truth knowledge of the computational classification of the systems. Furthermore, we analyze a few notable systems that are stretching the boundaries of our dimensional framework, indicating that more dimensions may be required. Finally, we discuss the analytical framework in relation to a higher-level description of live coding music performance and we discuss future studies that may be conducted to assess the validity of this approach.