Creating Printed Music Automatically

June 1996 61 Some of today’s music-score editing programs are capable of producing publication-quality scores. Some, such as Score (San Andreas Press), Finale (Coda), and Encore (Passport Designs), contain many powerful automation features in addition to notation capabilities. However, to produce scores as good as those music engravers and copyists create, the users must understand the positioning of many notational elements. For instance, should a slur appear above or below the affected notes? Should a tuplet appear between the slur and the notes or outside it? Scores produced by users who do not know the rules not only look wrong, they are difficult for musicians to read. Even if performers are not consciously aware that something is wrong, their subconscious reactions, conditioned through a lifetime of practice, will not be the same. In the past, a performer might have recognized and dismissed nonstandard notation as just amateurish. However, modern music features so many new and radically different notational systems that errors could become serious obstacles to the correct interpretation of a composition.1 Most users of notational software have little or no music copyist training, and musicianship does not guarantee notational skills. Even professional composers fail at many notational tasks if they have not had explicit copyist training. The ability to notate music has very little in common with the ability to compose or play it. Unfortunately, we do not have the rules for notating music in a prescriptive form, that is, one that a computer can use. Music copyists take years to learn them. For the most part, books present these rules in descriptive form using examples.1-3 Individual rules by themselves present little problem to notational software. It is the interaction between the rules that is so difficult to capture. This article presents a partial solution to this problem: How can users with little or no copyist training create publication-quality printed music? The solution, a program called MusicEase, applies constraints to notational information the user enters, automatically arranging graphical elements “correctly.” This can also speed up the notation process, since the copyist doesn’t have to make as many decisions or enter as much data. MusicEase incorporates a constraint-based technique to calculate the complex interaction of notational elements. Basically, it is a WYSIWYG editor with a menu system for novice users and keyboard shortcuts for advanced users. It contains most of the features of modern word processors, such as zooming and page preview. It also imports and exports standard Musical Instrument Digital Interface (MIDI) files. I wrote MusicEase using muLisp. Al Rich and David Stoutmeyer of the Soft Warehouse in Honolulu created muLisp, an MS-DOS version of Lisp. muLisp incorporates many of the ideas of Common Lisp and other modern Lisp systems, Creating Printed Music Automatically