New technology sometimes makes the world around us look unrecognizable. Photo illustration by Lisa Larson-Walker. Photos by the Library of Congress. Computers can write music now. They’re actually not awful at it. And they’re much quicker and cheaper than human composers, without any of the ego or ambition, making them an appealing choice for anyone who needs a tune on a tight budget. You might soon hear songs written by artificial intelligence playing in the background of radio ads, YouTube shows, or video games. A.I. has not yet penned a Top 40 hit. But it gets more talented every day. It’s likely a matter of time before a song composed entirely by a computer is rocking dance floors and climbing pop charts. The way a computer learns to compose is by listening to whatever music you feed it and then analyzing the patterns it finds. Which raises the question: Who gets the songwriting credit—and banks the royalties—when the composer is a neural net that wrote its hit jam after imbibing, say, the entire catalog of the Beatles? Would you divvy credit between Lennon, McCartney, and whichever hoodie-clad coder programmed the software? When I spoke to the general counsel of BMI, an age...