Drum patterns are fundamental to popular music’s soundscape. But the majority of music-theoretical scholarship about drum patterns focuses on their rhythmic and metric features, and there is no widely adopted method for analyzing how drum patterns help express form across complete songs. Grounded in a corpus study from the
Billboard Year-End Pop Airplay Songs charts from 2012–2021, this article introduces an analytical method that succinctly depicts the main characteristics of post-millennial pop drum patterns in order to highlight the significant and specific ways they help express formal boundaries, teleological functions, and formal motion. Drum patterns in this repertoire are typically a variation of a standard rock or four-on-the-floor pattern, and my context-based analytical system frames drum patterns as different realizations of three parameters: number of layers, rhythm, and instrumentation. A song’s multiple drum patterns can be analyzed and compared according to these characteristics, and these characteristics can also be used to classify drum pattern changes. In the second half of the article, I present analyses that, in addition to showcasing the system’s utility, emphasize two broad points: that drum patterns can be a primary expresser of teleological functions within individual sections, across formal cycles, and throughout complete songs; and that drum patterns can help express post-millennial pop’s conventional layouts and more novel formal designs.