David Cope is a person who teaches computers how to create music, just like how your parents teach you how to write and draw. He has created a computer program that can create original music by itself without any help from humans. It's kind of like a robot that can make beautiful music without needing a person to play the instruments or sing.
The way it works is, David Cope programmed the computer to understand the different components of music, like notes, rhythms, harmonies, and melodies. Then, he taught the computer how to analyze music that already exists and use that knowledge to create new music that sounds similar but is different enough to be unique.
So, basically, David Cope taught a computer how to make music by itself, and that's pretty cool!