Cloud Generator is a software sound synthesis, developed in the mid-nineties, dedicated to the computer music application of granular synthesis.
Background History – Cloud Generator has been developed for computer Macintosh at CCMIX in Paris (formerly called Les Ateliers Upic) by Curtis Roads in 1995, in collaboration with John Alexander, his student. The project is dedicated to the use of granular synthesis and appears as a refinement of the various software developed by Curtis Roads between 1988 and 1992. The software developed in those years were characterized by a degree of difficulty of use, since it forced the user to the knowledge of C language, which is why Cloud Generator, also made in C, is designed to combine the most interesting functionality of the previous software in a single environment with a graphical interface simple and intuitive. Cloud Generator was developed to respond well to educational needs as well as experimental compositions, always from the perspective of granular synthesis. In 1998, Curtis Roads and Alberto Campo handled the implementation of Cloud Generator in Creatovox environment.
The C language – The choice of C language was made to return a software easier to use. Users would be able to act directly on the code and develop, where appropriate, new Unit Generators, even if it means sacrificing computational speed. In principle the adoption of C would also have a greater portability, which is in practice not affected by the choice of using a non pure C language but a mixture of C, Csh (Cshell interpreter) and CPP (a preprocessor of C), which did not make it fully compatible with any of these languages.
The interface – As we mentioned, Cloud Generator is equipped with a graphical interface, inspired by the signal generators of the electronic music centers, through which control the various parameters useful for granular synthesis. Thanks to the virtual console, can handle values for density, amplitude, duration, frequency and range of grains, or control the stereo spatialization (Pan), the type of output (Wave or Text) and the type of waveform: Synthetic or Granulated.
Synthetic Mode – In this mode, user can get the grains from different types of sound wave form: sine, triangle, sawtooth or hand drawn.
Granulated Mode – Select the Granulated mode, however, the user can get their grain by pulling segments of external file imported into Cloud Generator. Activating this mode is also possible to activate a new function (Selection Order) to extract grains in parts of the source file selected in three different ways: random, statistical or progressive.
Output – Cloud Generator allows you to get two different file formats: AIFF, and text. The latter format is readable by a plotter to obtain a graphic score. More information can be found in the book Microsound by Curtis Roads.
For this topic I’ve read.
 Keeril Makan, An Interview with Gerard Pape, Computer Music Journal, Vol. 27 , 2003.
 Curtis Roads, Microsound, The MIT Press, 2001.
 Alex Di Nunzio, Genesi, sviluppo e diffusione del software Music N nella storia della composizione informatica, Thesis, Università di Bologna: D.A.M.S. Musica, 2010.