Lecture by Professor Mehran Sahami for the Stanford Computer Science Department (CS106A). Professor Sahami gives a lecture on data structures; he demonstrates this by showing the class how online music companies sort and classify their music. CS106A is an Introduction to the engineering of computer applications emphasizing modern software engineering principles: object-oriented design, decomposition, encapsulation, abstraction, and testing. Uses the Java programming language. Emphasis is on good programming style and the built-in facilities of the Java language.