Zbu rGyalrong, a language spoken in northwestern 'Barkhams county, shows a tone and stress system akin to what is commonly known as pitch accent. The system attested in Ngyaltsu variety shows numerous peculiarities, though very recognizable as part of the common rGyalrong pattern. In this report, the attested system will be described, particularly through its interaction with verbal morphology. The surface tone will be shown as derived from a series of interactions between different types of stems and prefixes. Finally, the probable diachronical development or retention will constitute a final point of this discussion.