The renowned American architects Sullivan, Wright and Mies van der Rohe are the center of attention in the composition Ekphrasis [Continuo II], even though originally Berio had no such thing in mind: "While I was working on Continuo, it was not my intention to compose a metaphor for architecture, or write a homage to the famous Chicago architects... Neither did I refer directly to the amusing but nevertheless solid constructions by Renzo Piano... However, as the work progressed I became aware that this was exactly what had happened." (Berio) For all that, Berio did not aim at following a formal "architectural course" but at creating a "continuously ever-changing landscape of sound, formed out of a grid of recurring patterns" by way of an internal musical process. Coro (1975/76) once again puts the focus of the compositional material on folk music, but not in the same way as for instance in the Folksongs (1964), which were, essentially, original instrumentations. In Coro the composer rather dealt with "different folk music techniques and sound gestures from different cultures," which were "combined occasionally, without referring to specific songs in any way."