A key function of prosodic prominence is to mark the most informative words in an utterance. However, informativeness has been conceptualised as, e.g., focus, given/new status or predictability; it is not clear how these are related. Furthermore, prominence is constrained by metrical prosodic structure. We present a new framework for prominence production: informativeness and prosodic factors are constraints on the probabilistic alignment of words with metrical structure. Informativeness operates on two levels, focus and lexical oaccentabilityo (predictability, part-of-speech). Foci align with nuclear accents, however, this is affected by prosodic and oaccentabilityo constraints. Accent prediction models (nuclear, non-nuclear, or unaccented) are presented for the Switchboard corpus. Consistent with our predictions, nuclear accents are more likely later in a phrase, and on focused words. The likelihood of nuclear and non-nuclear accents is affected by prosodic constraints (e.g., rhythm) and oaccentabilityo. The implications for the role of prosody in language production are discussed.