Automatic Justification and Line Breaking of Music Sheets

Automated music formatting helps composers and copyists to speed up the process of music score editing by facilitating complex evaluations needed to produce music sheets in terms of symbol positioning, justification, etc. Music justification is a complex task to be automatically performed. It involves the evaluation of a large number of parameters and requires context evaluation. In this paper, the approach adopted in a justification engine of a European Research project is presented. The approach solves many of the problems of music justification: alignment of simultaneous symbols in polyphonic music, spacing dependent from the duration of the figures, compactness and readability of the resulting measure, justification of both main scores and parts. In the paper, several justification algorithms are described and compared. Stretching and shrinking of measures is also possible, while keeping the justification through a tuning parameter. The resulting algorithm can also handle automatically many music notation exceptions: for example time inconsistency of the justified measure and presence of non-durational figures, grace notes, change of clef/key signature, etc. The solution proposed presents a module for music line-breaking. This is included in the justification engine as an option for visualizing and printing right margined music sheets. Several examples are reported to highlight both the problems and the solutions adopted. Index Terms: user interface, automatic formatting, music sheet, music formatting, space management, justification, beat-line, simultaneities, line breaking.