Csound is a computer music software that belongs to the Music N family. The first version was built in the mid-eighties, over the years has undergone at many changes that have improved performance and expanding its fields of application. Csound is still used and open source, supported by a large community of reference. The current version is 5.
Background History – The first version of Csound was finished after a long research conducted by Barry Vercoe in over a decade. In 1968 he developed the Music 360 which was followed a year later, by Music 11. In the early eighties, however, Vercoe has been dedicated to the problems of the interaction between computer and live performer, realizing the Synthetic Performer. All of these activities has allowed Barry Vercoe to realize, in 1986, at the prestigious MIT, Massachusetts, a new language for computer music, the latest among the Music N and also the most durable. On the birth of Csound, beyond the earlier work by Barry Vercoe, has also greatly affected the changing state of technology of those years. Besides the availability of computers faster and cheaper than those available in previous years, also engraved the spread of the C language that guaranteed portability and ease of use.
Relations with predecessors – Previous experience of Barry Vercoe, as we have just mentioned, have played an important role in the birth of Csound, and it is clear, then, that the latter holds an close relationship with software and systems developed over the earlier years. Apart the indirect relationship of descent with the Music IV, Csound holds a particular connection with the Music 11, so that the code of this could be read with Csound. Equally interesting and important is the relationship with the Synthetic Performer. Being programmed in C, some features of this particular system were adapted for Csound.
News – From the earliest years, Csound was appreciated for some news that positively distinguished him from his older ancestors as Music IV and Music V. Is it necessary to remember first the distinction between audio and control signals (which have already introduced with Music 11 and then improved with Csound, where these are identified simply by prefixing the letter K or A to the variable name), that thanks to the differentiation of sampling frequency, permitting a reduced workload on the CPU and therefore better performance. Csound was designed to bring together the best you could get from the C language, the Fortran and assembler. With later versions were added several other features that have contributed to making Csound a professional program and flexible to different needs. Among the many aspects that could be cited at least remember the adoption of the shortcuts (which made it possible to streamline and speed up the compilation of the code, very important in a program based on an alphanumeric approach), the implementation of graphical interfaces, numerous utilities, using in real-time, the adoption of the single format .csd (which replaced the double format .orc, for the orchestra, or instruments, and .sco for the score section) and more. All this has contributed to the Csound language training useful for many applications in computer music. All this has contributed to make Csound a professional language useful for many applications in computer music.
Real Time – One of the most important Csound feature (compared to previous Music N languages and compared with the needs of composeres interested in the use of computers in music) was the ability to use Csound in real-time applications. Although today there are no problems to the use of Csound in real time, it was a novelty introduced gradually. The first version of Csound for real time was released in 1990 by Barry Vercoe. On that occasion, were also introduced other innovations such as the implementation of FOF synthesis (based on CHANT software developed at IRCAM in Paris) and the implementation of the Phase Vocoder, modeled on one developed by Mark Dolson. This first version was followed in 1996 by a new version that improved, in particular, the use of MIDI in the working environment. Respect to the real-time version also remember CsoundAV, developed by Gabriel Maldonado (an independent researcher) and designed to work with not only audio but also video graphics.
Community – In addition to technical issues, there are also other aspects that have contributed to making Csound a very popular software. First, it must be said that Csound is available as a free download from the official website, which has encouraged the formation of a large community of reference concerned to the distribution and development of more efficient versions and utilities, that increase or improve the potential of software. All this has contributed to its widespread use in private but also in centers dedicated, for various reasons, to computer music. The community of reference today as offers valuable support for the resolution of various problems you might encounter while using the software. This thing finally allowed to have a vast amount of Web resources and documents that help you to use the program.
Utilities – Throughout its history Csound was joined by numerous other software or utilities that have contributed and still contribute to facilitate the use of a language that with his alphanumeric approach is still rather inconvenient. From Cscore, one of the first utilities developed by the same Barry Vercoe and designed to help you to write the score file, then you have had several utilities including Cecilia, a graphical interface for Csound, Blue (Java-based environment composition), winsound (Csound version for Windows), Macsound (Csound version for Mac), QuteCsound (a working environment with a graphical interface) and WinXound (editor for Csound and CosundAV).
Publications – Finally, there are publications devoted to Vercoe software that help in understanding the use and facilitate the application of Csound in computer music. One of the reference books is The Csound Book by Richard Boulanger. In Italy was published The Virtual Sound by Riccardo Bianchini and and Alessandro Cipriani. Both texts provide a general overview about the different features of the program as well as more specific insights. Also interesting is Cooking with Csound: Woodwind and Brass Recipies by Andrew Horner and Lydia Ayers. This is a text that contains numerous examples that reproduce sounds of traditional instruments. From this point of view is very useful The Csound Catalog, a code library ready for use. In addition to print publications should be mentioned also the virtual journals like The Csound Journal and The Csound Magazine. More information can be found on the official website: www.csounds.com.
For this topic I’ve read.
 Barry Vercoe, Foreword in The Csound Book, edit by Richard Boulanger, The MIT Press, 2000.
 Barry Vercoe, Dan Ellis, Real-Time Csound: Software Synthesis with Sensing and Control, Proceedings of International Computer Music Conference, Glasgow, 1990.
 Barry Vercoe, Extended Csound, Proceedings of International Computer Music Conference, Hong Kong, 1996.