Why can no system of musical notation show every detail of a performance exactly?

No system of musical notation can capture every detail of a performance because notation is inherently an incomplete and imperfect method of preserving or communicating musical sound.1

In practice, no notational system can handle all primary elements—pitch, duration, timbre, and volume—with total precision. Most systems prioritize a selection of these elements, often leaving subtle gradations of tone, attack, or timing to the performer’s interpretation.12

Furthermore, notation is often limited by the aesthetic and cultural context of its time. For instance, Western staff notation is frequently ill-equipped to represent non-Western scales, microtonal intervals, or music where the concept of a stable "note" is foreign. Even in complex modern styles like chance music, notation is often deliberately imprecise to allow for performer freedom, while in other contexts, it may be too clumsy to clearly indicate unconventional techniques or specific dynamic markings. Ultimately, performers act as interpreters who must bridge the gap between the written page and the actual sound, relying on tradition, scholarship, and personal taste to fill in what the notation leaves unsaid.2345