Luciano Berio,(October 24, 1925 – May 27, 2003) was an Italian Composer. He is noted for his experimental work (in particular his 1968 composition Sinfonia for voices and orchestra and his series of numbered solo pieces titled Sequenza) and also for his pioneering work inelectronic music .
In a series of interviews with Rossana Dalmonte in 1980- 81, Luciano Berio explained that the Sequenzasare unified by three traits: virtuosity, idiomatic writing, and above all a “polyphonic mode of listening” that challenges the way a listener hears a composition. In the Sequenza XI for Guitar, Berio does this by establishing four simultaneous layer s, which are defined by the type of material used. Each of these layers pursues a different developmental path by generating tension through a technique that can be described as in - and out- of - focus. As the level of tension or focus heightens in a layer,the structure is clouded or out of focus. When Berio creates static or low- tension structures, the work becomes more in focus. In this study, I examine the roll of levels of focus in each layer and the interaction of each layer to the whole of the composition.