We discuss the characteristic features of several composers. Why do we know it is Mozart, when we hear a piece of Mozart? The music of Mozart is different from the music of Bach, Beethoven, or other composers, but how and why? In this context we will take a closer look at the music of Mozart, Beethoven and Schubert. Furthermore, we discuss why we can remember some music well and other music not, by using pieces from the music of the iconic film “2001: A Space Odyssey”. There is also some music of which we know immediately what it is, when we hear only a few bars at the beginning. “The Fate Symphony” of Beethoven is a perfect example of this kind. A regular rhythm generally helps us to recall the music’s origin. Finally, Pictures at an Exhibition of Mussorgsky and the music of the Beatles are viewed through a magnifying glass.