A lot of electronic dance music has a very characteristic feature: The music gradually builds, and then suddenly changes to a different rhythm, pitch or instrumentation. It feels like the tension of riding up a rollercoaster, just before you go down. Fittingly, this music phenomenon is called the “drop”.
In the seconds before the drop, you expect something to happen, but you don’t know exactly when it will happen or what is coming. The lead-up is slightly different for each song and not as predictable as some other patterns. In general, the way we process music depends on expectations. If you hear a half-finished melody, your brain expects certain notes to complete the phrase. Drops in dance music don’t follow that familiar pattern. They’re unpredictable by nature, and scientists are trying to figure out what happens in your brain when you hear one.
Link: Full Article – How Your Brain Responds When The Bead Drops