The final movement of Samuel Barber's piano concerto is undeniably daunting to soloist and orchestra alike -- and there can be no doubt that rhythm is its most defining feature. Its relentless quintuple meter is both the driving force behind the movement's diabolical moto perpetuo character and the fundamental source of rhythmic conflict. In fact, the unfolding of the entire movement can be understood in terms of a dichotomy between a "2+3" and "3+2" division of the measure, indicated by persistent rhythmic ostinati and the composer's frequent numerical designations. These ostinati and metrical divisions clearly correspond with the sections of the movement's form -- a seven-part rondo -- in which the refrain is characterized by simultaneous presentation of both metrical divisions, and each episode by a unified presentation of one metrical division.

I read this movement as a narrative corresponding to Byron Almén's archetype of Irony, and investigate questions of agency and narrative function in this somewhat unusual example. In the context of such an interpretation, the aforementioned metric dichotomy highlights marked episodes of rhythmic clarity, which provide temporary relief from an unmarked, chaotic refrain. The intensification of the refrain eventually leads to a liquidation of the quintuple meter and even quintuple subdivision of the measure altogether. Another level of irony becomes apparent upon consideration of the piece's conformance with traditional norms of the genre, wherein it would be tempting to think of the soloist as protagonist. Barber's soloist, however, represents the transgressive antagonist, mocking and undermining the orchestra's attempts at rhythmic unity.