Historical pianos ("pianofortes") from the Romantic era differ significantly from what is commonly thought of as the standard modern piano in terms of construction as well as touch and tone qualities. Such a difference, as historically informed practice on pianoforte has demonstrated in recent decades, has its roots in a musical framework vastly different from ours. Any evaluation of its qualities requires a thorough understanding of the aesthetic aspirations and technical resources that characterized pianism at the time. The purpose of this research is to investigate the interaction between pianist and piano based on its construction parameters. The nature of such interaction was modeled using a comparative analysis of documentary sources on piano technique that were either "modern" or "historical" (and "historically informed"). A "mechanical arm" was thus built, capable of delivering motion at the front of a piano key depending on its moment of inertia and the applied force. Thus, the intensity of sound was investigated as a function of applied force and average key downward velocity. The findings show consistency in the degree of variation in the construction parameters of a pianoforte and a modern piano and differences in respective techniques, due to differences in aesthetic aspirations.