Any musical process has an underlying abstraction or intermediate structure that guides it. The analysis of a musical work tries to find this abstraction. When composing, the musician uses this structure to generate new content.
Music information classification and retrieval systems make use of the abstraction in order to accomplish their task. The correct choice of an intermediate structure drastically conditions the application it is used for. Being the hierarchical structures inherent to music itself, however, they have not been widely adopted by the computer music community.
We will introduce the abstract data type Tree as a natural way to represent music, along with some successful applications of this intermediate structure.