What's the difference between i.e. and e.g.?
instrumental music that carries some extramusical meaning, some "program" of literary idea, legend, scenic description, or personal drama. It is contrasted with so-called absolute, or abstract, music, in which artistic interest is supposedly confined to abstract constructions in sound. It has been stated that the concept of program music does not represent a genre in itself but rather is present in varying degrees in different works of music. Only in the so-called Romantic era, from Beethoven to Richard Strauss, is the program an essential concept, and even there it leaves its mark on much music commonly considered "pure" or "absolute."