Compo is a language allowing to describe in a natural way simple or complex musical structures. By simply entering the form : You will get immediately the following result : Just Insert a D as an attribute to the main structure : Pronto, your tune is transposed a whole tone upwards (D = C + one whole tone) : Here is an example of a folk song : Take a look to our demos for a more complete idea of the great possibilities of compo. The simple syntax which is presented to you in the examples above is intended to allow any person who have learned the rudiments of musics to use compo. This level of use already allows an easy encoding of any kind of musical scores, in an intend of composition, analysis or sight-reading... However, for developpers, this simple syntax actually reveals only a little part of a great potential (in fact the language Common Lisp on which is based compo), allowing the development of many musical applications able to take advantage of its original presentation mode. The score fragments presented in this page, as well as the graphical objects that illustrate our demos (indeed, you really should take a look at them!) show the abilities of compo to be extended. In the first case, the score is generated by Common Music Notation, a system dstributed by the CCRMA. In the second case, the graphical environment used is Open Music, a powerfull musical representation system developped at IRCAM. In the two cases, the modular nature of the concerned systems, either compo, Common Music or Open Music, have made the interconnection possible. As to finish this introduction, just note that compo is downloable for free, and that its source code is open, as to allow its extension by anyone, in respect of the GNU-GPL license. So, feel free to take advantage of compo.