Is traditional music theory relevant to recent popular music, and how should it evolve? Traditional music theory assumes fixed scales, predefined tuning, and the clear transmission of well-defined pitches. Modern popular music challenges these assumptions, incorporating alternative tuning frameworks and uncertainty in pitch perception. Inspired by Cartesian doubt and phenomenology, the presentation advocates suspending biases, prioritising observation, and generalising cautiously. Pitch perception is more complex than commonly assumed. Similarly to how a physical line’s dimension can exceed one, tones may resist classification as a single pitch. Modern popular music follows principles that differ from those that historically shaped scale construction. A new theoretical framework suggests that the tones themselves can define the tuning system rather than conforming to a predetermined structure. Another hypothesis proposes that repetition in music takes advantage of multi-stable pitch percepts. A more precise understanding of musical evolution prevents misinterpretations and false conclusions. It enhances music technology and AI applications while fostering creative exploration beyond classical constraints. Western classical music theory is a specific system, not a universal truth. Understanding modern popular music requires observing how it develops rather than imposing outdated frameworks.