Goebl, Werner (2011) "Temporarily out of sync: Momentary temporal independence of a solo voice as expressive device," in Forum Acusticum Aalborg 2011 (European Acoustics Association, Aalborg, Danmark) p. 615-619.
Abstract: The solo part in music performance usually synchronizes well with the rhythmic-metrical context of the accompaniment, that is, the onsets of that part occur within certain temporal limits relative to the onsets of the accompaniment. This applies to a range of musical styles (e.g., classical music or Jazz) and ensemble configurations (from an orchestra to small ensembles or even piano solo). However, deviation from this synchrony may exceptionally be used as expressive device. This paper strives to explore those situations of temporal independence in various musical styles and ensemble sizes. In classical piano music of the Romantic period, this device is described as “tempo rubato in the earlier meaning” (Hudson 1994), referring to the temporal freedom of the melody hand relative to the accompaniment (e.g., in a Chopin Nocturne). For example, in Jazz performance, this effect may correspond to a significant delay of the (right-hand) solo relative to the beat for almost an entire chorus that is brought back in time at the beginning of the next chorus (as found e.g., in recordings of the Erroll Garner Trio). This paper reports on exemplary quantitative analyses of those situations of temporal independence and demonstrate its expressive effects through complex data visualization.