13-year-old pupil computed a Pythagorean C scale from Middle C (261.63 Hz) to C' (523.26 Hz) using monochord ratios (1:2, 3:2, halving, two‑thirds) and managed octave transpositions by systematic doubling/halving. Calculations align with Pythagorean tuning methodology: multiplicative reasoning and inverse proportionality applied with precision; resultant frequencies for C D E F G A B C' fit Pythagorean constructs. Analysis shows methodological rigor, clear notation and consistent units, linking ACARA v9 The Arts (Music) and Mathematics (Number and Measurement). Conclusion: exemplary mastery; recommend comparative study of Pythagorean versus equal temperament and hands‑on monochord or software verification. (Snap. Hum. la‑la, brief legalese.)