Algorithms and data structures for a music notation system based on GUIDO music notation

Many aspects of computer-based music notation have been previously discussed. The presented thesis deals with the process of converting a textual description of music into a conventional musical score that can be either printed or viewed on a computer screen. The chosen textual music representation language is GUIDO Music Notation, an adequate, human-readable format, which has been developed since 1996. Because GUIDO Music Notation is not solely focused on score representation but rather on being able to represent all logical aspects of music, the conversion of arbitrary GUIDO descriptions into a conventional score is not necessarily an easy or straightforward task. The thesis begins by introducing the three-layered structure of GUIDO Music Notation. The most important features of GUIDO are presented and compared to other music representation languages. The thesis continues to describe how GUIDO descriptions are first converted into a suitable computer representation. Then, automatic musical typesetting algorithms work on this inner representation. The major difference to other music notation systems lies in the fact that all implemented typesetting algorithms are described as GUIDO to GUIDO transformations. Each step of the musical typesetting process adds more richness to the GUIDO description. The final description, which contains all typesetting information, is then used for viewing and printing the score. In this thesis, the implemented music notation algorithms are described, some of them in detail; especially those parts of the musical typesetting process that have similarities to text setting, namely spacing and line breaking, are presented. An improved algorithm for spacing a line of music is discussed and it is shown how the resulting spacing more closely matches the spacing of a human engraver. Additionally, a new algorithm for optimally filling pages is presented for the first time. The implemented music notation system is used within several applications including an online music notation server which is freely available on the Internet using any standard web browser.