This paper will be of interest to individuals desiring a discussion of a method of scheduling processes in a real-time environment. In particular, this work is the result of a program developed by the author for musical control of a real-time digital synthesizer. It describes in a general sense an intervention-scheduling model. The intervention-scheduling technique is valid for real-time programming. An Intervention-Scheduling Programming Language (ISPL) is described in an overview sense.:P This concept requires the existence of triggers to mark and identify events in such a system. These triggers are defined in some detail and play a vital, flexible role in this difficult environment. Relationships are drawn with the parallel processes model and actors model.