Although he left an extended and varied output, including five major stage-works, several shorter dramatic pieces, a number of significant choral and orchestral works (not least the famous Sinfonia of 1968), and a sizeable body of instrumental and vocal pieces, the music of Luciano Berio is encapsulated in the Sequenza series running through 34 years of his creativity. Not only have many of them set standards for performance prowess and stamina, each embodies a redefining of the technical limits of the instrument, and through this, the establishing of an expressive profile that draws on its past evolution while facilitating its future development. Virtuosic yet communicative, the Sequenzas are a touchstone for the dialogue between performer and listener. In 1994, Berio invited the author Edoardo Sanguineti to pen epigraphs for each of the (then twelve) Sequenzas. These verses, which can be recited by the musician or read by the listener prior to performance, are not intended either as an explanation or illustration of content: rather, they aim to focus the listener's mind on the music to be heard.