Goffredo Haus is Professor of Computer Science at the University of Milan and Director of the Laboratorio di Informatica Musicale. He is the author of a system, ScoreSynth, for the manipulation of music pieces based on Petri Nets. The first six pieces show musical manipulations of the well-known canon Frère Jacques: the given piece, then a specular inversion, then retrogradation, then the output of a net model, of a deterministic version of the preceding model, and finally of an alternative output. Finally we hear a complete piece synthesized by the system.

Next is a project by the author of this lecture and text, Denis Baggi, developed at the International Computer Science Institute and at the University of California at Berkeley. It consists of a jazz rhythm section which, from a harmonic grid, plays in real time the parts of piano, bass and drums, with the kind of interpretation and substitutions jazzmen use to swing. Three knobs (labeled with Hot/Cool, Consonant/Dissonant, As-is/Free substitution) allow the user to control the style of the system.

The first piece is a typical structure of jazz, Rhythm Changes, basis of countless jazz tunes (I got rhythm, Lester leaps in, Dexterity, Anthropology), played initially as typed in, and then with various settings of the knobs: hot, dissonant, etc. To illustrate the use of the system, Baggi during the lecture plays a B^b soprano saxophone on top of the synthetic section, claiming that software engineering is about instruments to measure the performance of software and that he belongs to the category of computer scientists who use a saxophone to this end (when he has to apologize for a poor performance he uses a bop quote, that a rhythm section by itself is like solitary love-making and that interaction has to be preferred even at the cost of hearing him).

The next piece is a 12-bar blues with three choruses increasingly hot and dissonant, followed by Stella by Starlight, a standard played on the setting of the knobs a user would select to practice improvisation. Lastly there is a piece in which the oboe line is played on the keyboard of the synthesizer, while piano, bass and drums are played by the program on the same synthesis machine.

This piece is included in the enclosed Compact Disk.

The next project has many authors, among which Antonio Camurri of the University of Genoa, who has constructed a complex system to assist composers and musicians with techniques drawn from Artificial Intelligence. The first three pieces illustrate a melodic jazz improvisation by the system on a given harmonic grid - that is, the 'other half' of the preceding project which synthesizes a rhythm section, while this one produces a soloist. Lastly there is a composition by Corrado Canepa obtained with the system.

Yap Siong Chua, Professor at the University of North Florida in Jacksonville, proposes a study on pentatonic scales, which can be found in all cultures. The pieces have in common that they are obtained from scales consisting of five notes only, such as Auld Lang Syne, of Scottish origin. The last piece is a composition by the author, obtained with a computer, to illustrate the pentatonic technique.