How random is random on your music player?

本帖最後由 toylet 於 2015-2-20 00:00 編輯

There I was, walking to the railway station, minding my own business, when... bam!

Our song.

That's the gamble you take when you set your device to "random". Sometimes you get good songs, sometimes you get bad ones. Sometimes you get songs that remind you of someone that was once in your life.

I skipped it. Buddy Holly saved my mood, and saved the day.

Until home time. Hopping on to the Tube, press play. It was back. Our song.

How Random is Random? can be listened to on this week's episode of Tech Tent on the BBC World Service.

Don't be daft.



When we attach so much of our own emotion, be it a place, memory or person, into the songs we cherish, eerie coincidences brought up by shuffle or random functions can be unsettling.

Or in some cases just irritating. Five thousand songs, and it brings up three tracks by the same artist in quick succession? Come on now, that can't be right. This is supposed to be random!

Except, of course, it is random. Our brains just don't like it.

At the music-streaming service Spotify, developers have applied their finest chin-strokers to the issue. Users were complaining, they said, that their shuffle function was not random at all.

"Our brain is an excellent pattern-matching device," said Babar Zafar, a lead developer at Spotify, in an interview for Tech Tent on the BBC World Service.

"It will find patterns where there aren't any."
Play icons

Users were complaining in their droves, he said, that Spotify was somehow forcing music upon them. Conspiracies included the idea that record labels had struck up some kind of deal to make sure some artists are heard more than others. Mr Zafar dismissed that thought as hogwash.

"The problem is that, to humans, truly random does not feel random," said Mattias Johansson, a Spotify software engineer, in a response on the question-and-answer site Quora.

"So we got tons of complaints from users about it not being random.

"Last year, we updated it with a new algorithm that is intended to feel more random to a human."

Coincidental jazz

The fact is that the human brain, for all its brilliance, is a sucker for coincidences. And more importantly, given the topic of this article, the brain is also keen to believe that something not happening for a long time makes it more likely to happen next time.

The theory is known as the Gambler's Fallacy or the Monte Carlo Fallacy, owing to one memorable night in 1913 when the roulette ball fell on black 26 times in a row.

Players at the table were betting huge amounts in disbelief, expecting the normal "random" order of the world to be set right with each spin.

The very foundations of the billion-dollar casinos of Las Vegas are built on the fallacy. There is a pernickety bit of our brain that thinks if we did not win the last five hands of blackjack we are surely going to get lucky when the next hand is dealt.

When applied to how songs pop up on our music players, the fallacy means we, for some reason, think it less random when two similar songs play.

It is a lack of uniform distribution that throws us off, writes Martin Fiedler - a programmer who describes himself as an "average nerd".

Consider a playlist of 32 songs, he says, split almost evenly into three genres - 10 of genre A and 11 each of genre B and C.

A truly random playlist might spit out something like this: AACBBCBACABBCCACCCCABBACBACABABB

It is random, but it sure will not feel like it - and that block of four Cs in the middle there might be annoying. Particularly if they are jazz.

"This example, short as it is, already exhibits the two main problems of random shuffle algorithms," writes Mr Fielder.

"The first one is the burst of four adjacent C's in the middle of the sequence, the second one is the lack of B's in that area (there's no B for 8 slots, which is quarter of the whole sequence!)."

Music in uniform

So here is how Spotify solved the problem.

What our brains actually crave from "random" is that the three genres get spread nicely over the playlist.

Which, after a lot of mathematical magic, is what Spotify does now.

"Suppose we have a playlist containing some songs by The White Stripes, The xx, Bonobo, Britney Spears and Jaga Jazzist.

"For each artist we take their songs and try to stretch them as evenly as possible along the whole playlist."

Spotify's algorithm takes into account how long a playlist is, and how many of each type of song there are. So if there are four White Stripes songs in the list, they will each appear at roughly 25% intervals.

There is no chaos here - instead a highly structured and sophisticated way to trick your brain into thinking it is getting a great mix of shuffled tracks... that may or may not remind you of your ex.



講真如果我有五千首唔同類型嘅歌, 一定唔會 random play, 即使會, 都會只抽一首播
但唔知有咩 player做到? 係只抽一首播, 播完即停

另外, 有啲歌係有關連, 有次序嘅, 例如 A1 播完後, 下一首一定係 A2,
如果 random play 就要好好彩先做到(正常1X首都唔易做到)
可能有人話將兩首歌合埋做一首咪得囉, 但偏偏又想 A2係一首獨立嘅, 有機會抽中淨播A2
咁煩㗎~ ...A1+A2一首, 另加一首淨 A2囉
唔得喎, 聽完一次 A1+A2, 遲啲又聽一次淨 A2?

上文好似冇提 iTunes 嘅 Genius隨機播放, 唔知有冇用家分享下佢得唔得?


上文好似冇提 iTunes 嘅 Genius隨機播放, 唔知有冇用家分享下佢得唔得?
CMZ 發表於 20/2/2015 23:27

要 random 每首歌都播一次先重複, 睇怕要 Playlist 記住邊首播過了!


提示: 作者被禁止或刪除 內容自動屏蔽


本帖最後由 hpkpk123 於 2015-2-22 14:49 編輯

其實有冇人知點解windows media player幾年黎都冇更新過


Random 播一次同一隻碟,求其一部碟機或 software 都應該得
問題係 random 得唔啱心水,亦都係上面水蛇春咁長篇嘢想講嘅問題


其實有冇人知點解windows media player幾年黎都冇更新過
hpkpk123 發表於 22/2/2015 13:13

因為 player 和 codecs 兮 分開??
player 應該無乜需要改!


屋企foobar random play
但會粗略edit下個play list 例如飛走vocal off
最緊要keyboard 要有 forward hotkey