A powerful and efficient algorithm has been designed to deal with the critical timing problem of the MIDI messages. This algorithm can convert note events stored in a natural way to MIDI messages dynamically. Only limited memory space (the buffer) is required to finish the conversion work, and the size of the buffer is independent of the size of the original sequence (notes). This algorithm's real-time variable properties suggest not only the flexible real-time controls in the use of musical aspects, but also the expandability to interactive multi-media applications. A compositional environment called MusicSculptor has been implemented in terms of this algorithm.