How the brain perceives a random selection of songs

It happens that you listen to songs in a random order, and then suddenly one after another the songs of the same group sound. What a mess? What is this random order? Such questions arise in the normal human brain, which is completely not adapted to the perception of accidents .

For example, if you take a playlist of 30 songs: 10 songs each of the three performers A, B, and C, then a random sequence might look like this:
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AABCBACABBCCACCCCABBACBACABABB

The brain will be utterly perturbed by such a random sequence, especially the block in the middle, where 6 of 7 songs are assigned to the performer C.

It has long been known that as a result of evolution, the brain learned to find relationships between any and completely unrelated events (a comet flew by - a war began; a new director of the company came - stocks fell / rose, see also the phenomenon of "national signs"). We recognize images where there are none. This is due to the excellent ability of the brain to recognize images, because of which you have to put up with a lot of false positives.

Such features of thinking interfere with the normal perception of random music, and not only her. The phenomenon is well-known in the gambling industry, it even got its name - the false conclusion of Monte Carlo or “player error”. It is connected with the fact that a person is usually not aware, on an intuitive level, that the probability of an outcome of a random event does not depend on previous outcomes. It seems to most people on an intuitive level that if a black color appears on the roulette wheel several times, the probability of red falling out increases.

When it comes to music services, developers have to solve the problem. For example, the developers of Spotify last year changed the algorithm for issuing random songs , so that it de facto ceased to be random. But does not cause irritation in the audience.

Now the algorithm takes into account each artist and evenly distributes his songs throughout the playlist. Spotify hopes to reduce the number of complaints that the service allegedly "promotes" individual performers, putting their songs more often than others.

PS Read more about the Balanced Shuffle algorithm here .