Requiem per una veu perduda (Requiem for a lost voice in Catalan) is a piecefor mezzo-soprano with on-stage effects processing and recordedelectroacoustic material. The electroacoustic material consists mainly ofsynthesised vocal sounds and the pitches for the mezzo-soprano part weredefined based upon the functioning of the speech synthesis methodsused. This paper outlines the basics of one of the speech synthesis methodsused to compose the piece and introduces the scheme for the definition ofthe pitch material for the singing. The relationship between the speechsynthesis methods and the pitch material establishes the structuralfoundations of the piece.