The hook is the part of the song that will not leave you alone. The hook is not the chorus. The hook is not the melody. The hook is the thing that grabs you by the collar and says you are not going anywhere. The hook can be two notes. The hook can be one word. The hook can be the way a drummer hits the snare on the two and the four. The hook is the smallest possible piece of music that contains the entire song.

Keith Richards wrote the hook for Satisfaction on a cassette recorder in a hotel room in the middle of the night. Five notes. Dah dah dah dah dah. He went back to sleep. In the morning he did not remember recording it. The tape ran out and the rest was snoring. Five notes and then snoring. Those five notes are worth more than most people's entire catalog. That is the hook. It comes to you. You do not go looking for it. It arrives and if you are lucky you press record before it leaves.

Motown understood the hook better than anybody. Berry Gordy had a rule. If you could not sing the song after hearing it once you did not have a hook. One listen. That was the test. The Supremes. The Temptations. Marvin Gaye. Stevie Wonder. Every Motown record had a hook that passed the one-listen test. Berry Gordy was not a musician. He was a factory worker who understood that the hook is an assembly line for the ear. The hook goes in and it does not come out.

On the corner the hook was survival. If you did not hook them in the first four bars they kept walking. The verse could wait. The bridge could wait. The hook could not wait. The hook had to be the first thing they heard because on the street you do not get a second chance. The club gives you a whole set. The radio gives you thirty seconds. The street gives you four bars. If the hook does not land in four bars you are playing for pigeons.

The algorithm thinks it understands the hook. The algorithm measures the hook in seconds. Skip rate. Completion rate. Save rate. But the algorithm does not know why a hook works. The algorithm knows that a hook works. The algorithm can tell you that a certain frequency at a certain tempo makes people stop scrolling. But it cannot tell you why Keith Richards heard those five notes in his sleep. The hook is not science. The hook is a ghost that visits you at three in the morning and if you are holding a guitar when it arrives you might catch it and if you are not it is gone forever. The hook does not care about your algorithm. The hook cares about your ear.