We examine the phonetic differences in the realization of word stress and phrasal accent in two dialects of Irish: Connemara Irish and Munster Irish. We find significant differences between the phonetic cues utilized in the realization of the two levels of prominence as well as significant differences in the alignment of these levels by dialect. (Stress and accent are both realized through interactions with pitch range and are aligned on a single syllable in Connemara Irish, while stress and accent rely on separate phonetic cues in Munster Irish and may be realized on different syllables within a word.) By disentangling the two levels of prosodic prominence in Munster Irish, we are able to motivate a hypothesis into a diachronic catalyst that resulted in a phenomenon of stress shift in the Munster dialect, which is not present in most other varieties.