Abstract:

The ToolBook II(TM) multimedia authoring environment has been successfully used to develop Music educational software under the projects of the Computer Music Lab of the Federal University of Rio Grande do Sul (UFRGS,Brazil). In this paper are reported the extensions made to this environment's musical capabilities during the development of the Rhythmic Training System (or STR, which stands for Sistema de Treinamento Rítmico). These extensions were necessary to allow the random generation of rhythmic sequences, in order to simulate a "rhythmic dictation", an exercise traditionally carried out in Music classes. Such a task demanded the manipulation of MIDI files at the level of musical events, and that is not directly offered by ToolBook's high level of abstraction functions.

The solution proposed by this paper is to employ dynamic-link libraries (DLLs), which can be easily linked to ToolBook applications. In the application example presented here, a sequencing function available in ToolBook plays a temporary MIDI file, created by the function offered in the DLL based in parameters computed by the calling program. The use of temporary files has also proved to be a satisfactory solution to simplify the communication hold via the MIDI protocol.

Although the described solution satisfies STR's design specific requirements, the proposed alternatives for both the extension of ToolBook's musical capabilities and the exchanging of MIDI messages may be applied to other similar projects.