The musical score for a four-movement symphony can be well over a hundred pages long. It’s interesting, though, to see how much great music is written on just a page or so. Country, folk, and rock tunes, pretty much anything that’s made the pop charts since World War II, can be expressed as a few lines of text with chord symbols written above. Jazz musicians prefer to learn tunes by ear, but when they have to read they use a similar system: a melody written with chords above, usually one page or