Where does beat collide?

Joseph Sauveur's 1701 Système général des intervalles des sons described the periodic waxing and waning of loudness heard when two tones of nearly equal frequency sound together, which he named beats (battements), and he was the first to use them to determine frequency differences. Helmholtz's 1863 Die Lehre von den Tonempfindungen (On the Sensations of Tone) gave the seminal account of beats and their part in roughness and dissonance. Here a beat is an interference effect whose rate equals the difference between the two frequencies, so pipes at 100 and 103 cycles per second beat three times a second, and it is not a contraction of the heart, the pulse of musical meter, or a news assignment.[1][2]

Unit

One cycle of the loudness fluctuation, at a rate equal to the frequency difference of the two tones

Recovery means

Not applicable

Measured by

Counted by ear or read off a waveform as the beat rate, equal to the absolute difference of the two source frequencies

Cooper and Meyer's 1960 The Rhythmic Structure of Music treated the beat as the regularly recurring pulse that underlies meter, the even series of stresses a listener taps a foot to. Lerdahl and Jackendoff's 1983 A Generative Theory of Tonal Music gave the seminal formal account, defining beats as idealized points in time that a listener projects onto the music and organizes into strong and weak positions. Here a beat is a perceived unit of musical time that carries no fixed length in seconds until a tempo is set, and it is not a throb between two tones, a contraction of the heart, or a reporter's territory.[3][4]

Unit

One point in the metrical grid, its clock length set by the tempo

Recovery means

Not applicable

Measured by

Inferred from listeners' tapping and from the notated meter, and located as evenly spaced points across the music

Fishman's 1980 Manufacturing the News analyzed the beat as the territory a reporter is assigned to cover, a fixed round of places and sources through which news is routinely gathered. Magin and Maurer (2019) trace the practice to the end of the nineteenth century in the United States and describe how dividing coverage into beats structures a newsroom and builds a reporter's expertise and source relationships. Here a beat is an organizational assignment, a topic or geographic domain such as courts, city hall, or science, and it is not a heart contraction, an interference throb, or the pulse of musical meter.[5][6]

Unit

One assigned domain of coverage, defined by topic or geography

Recovery means

Not applicable

Measured by

Delineated by newsroom assignment and observed as the reporter's regular round of sources and locations