ENP-Expressions, Score-BPF as a Case Study

ENP2.0 is a music notation program written in Common Lisp, CLOS, and OpenGL. ENP provides a rich set of notational attributes called ENPexpressions. In this paper, we give an overview of the properties of ENP-Expressions. The underlying system used to handle the graphical representation of ENP-expressions is discussed in detail. A special attention is given to an expression called Score-BPF. The specific problems arising from the need to visually synchronize the linearly spaced (Score-BPF) and non-linearly spaced (music notation) objects is also discussed. Finally, some examples are given on how the properties of Score-BPF can be used to implement various types of editors in ENP.