Why is there a practice of chanting the Priestly Blessing melodically?

This source-based Torah study examines the question: Why is there a practice of chanting the Priestly Blessing melodically? The canonical Hebrew discussion develops the issue through the weekly Torah portion and the sources cited there, preserving the distinctions, tensions, and practical implications of the original text. This localized discovery layer does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.