While visual signals that accompany spoken language serve to augment the communicative message, the same visual ingredients form the substance of the linguistic system in sign languages. This article provides an analysis of visual signals that comprise part of the intonational system of a sign language. The system is conveyed mainly by particular actions of the upper face, and is shown to pattern linguistically and predictably in Israeli Sign Language. Its components, aligned with prosodic constituents, are associated with particular but general meanings and may be combined to derive complex meanings. The Brow Raise component is functionally comparable to H tones, signaling continuation and dependency, and characterizing yes/no questions and the if-clause of conditionals, for example. The component Squint instructs the addressee to retrieve information that is not readily accessible, and characterizes relative clauses, topics, and other structures. The details of the componential analysis proposed here explain why the two components together co-occur on such seemingly diverse structures as yes/no questions about mutually retrievable information and counterfactual conditionals. Like auditorily perceived intonational melodies, the visual intonational arrays in sign language provide a subtle, intricately structured, and meaningful accompaniment to the words and sentences of language. (Contains 1 table, 12 figures and 24 footnotes.)