This document discusses a new information-structural semantics for English intonation that integrates intonation structure into compositional semantics. It argues that the literal meanings of pitch accents and boundaries can be analyzed along two binary dimensions: theme/rheme and agreed/not agreed. Many discourse meanings attributed to intonational tunes arise via conversational implicature from these more basic literal meanings. An example is provided to illustrate how pitch accents serve to distinguish themes from alternative sets presupposed by the speaker.