During his PhD studies, Epa's research investigated the practicability of diverse electroacoustic music compositional approaches and formats which were applied in a series of works that explored specific relationships between real-world and abstracted sound materials, through the strategic use of pitched, melodic and non-pitched materials (and specific characters and behaviors of those materials) as integral elements in the compositional process. All compositions were related to Greece at many different levels, in direct or symbolic ways. Epa was examining all these different levels in a musical way via electroacoustic music and presented unique aspects of Greece within an entirely innovative musical frame.  In addition, Epa was exploring new electroacoustic music territories by undertaking a journey from real-world instrumental and concrete soundworlds based on aspects of Greek culture, music, mythology and religion, towards abstract soundworlds.

Real-world soundworlds consist of sounds, spaces and places that can potentially communicate human experiences: familiar impressions, aural images and evocations for the listener. Abstract soundworlds that emerge from real-world ones through various transformation processes also consist of particular sounds, spaces and places which can be very different from the ones emerging from real-world soundworlds. Developing innovative techniques and processes that explored the intersections, contrasts, connections and discourse between the two, was Epa's main overall research field.

The concept of external space as well as the exploration of motion and growth processes in spectral space, which were both established by Dennis Smalley in his article: Spectromorphology: Explaining Sound-Shapes (1997) were examined in both real-world and abstract soundworlds throughout Epa's portfolio works, all of which were in stereo format.