Go up to Developing CONCERT Tools Go forward to Concert Simulation and Debugging

Composing Concert Scores

Composing a concert score by constructing a Java session program as depicted in Concert Example and Concert Composition is conceptually simple but still a task too low-level for typical users. Various coordination languages, based on high-level declarative or visual abstraction models, can be used to construct sessions in a more comfortable way and generate the corresponding Java classes.

As an example, The following figure sketches the essentials of a possible visual programming interface; this picture contains the same same information as the concert score described in Concert Example):

• Each vertical bar represents an instrument ensemble with arrows describing their interaction with the concert score (leftmost bar):
• Green (thick) arrows from the score denote the activation of the corresponding ensemble; annotations describe the argument strings passed to each activated ensemble.
• Blue (dashed) arrows describe beat synchronization between score and ensemble causing the score to be (potentially) blocked.
• Black (thin) arrows describe the activation of general instrument methods such as hiding an instrument, showing it again, bringing it into independent execution mode and back into follower mode again.
• Those times when ensembles are hidden are denoted by dashed vertical bars; those times when ensembles are operating in independent mode are denoted by thick vertical bars.
• A red arrow to the score finally signals the termination of each ensemble.

While the details of graphical representations may vary, it should be clear that the concert model described in this paper can be visually described in a unique way such that the corresponding Java classes are generated by a compiler. The only remaining task is the association of instrument ensembles to player ensembles and the definition of access policies, which can be also supported by graphical standard forms.