This article is based upon the dictation, composition and conducting of two "crossover" orchestral works-"Concerto of Eight Sounds" and "Bunun Legend" composed by the author. The aim is to point out the technical and aesthetic problems of "crossover" performance. The central point of view is to indicate the special characteristics of "crossover" performance: different systems, custom-made, notation...problems and derives the conclusion that "crossover" is a process but not the end of composition.