iTunes: Just how random is random?

By David Braue on 08 March 2007

Say You, Say What?
Using Excel, we collated the results and counted the number of times that each song and artist appeared in the playlists iTunes had generated.

All things being equal (and random), one would expect that a field of 1300 song slots would provide enough opportunities for each of the 56 artists to be equally represented. However, this was not the case. In fact, even though each specifically chosen had five songs in the library, there was a large discrepancy between the most popular and least popular artists.

Top 10 artists

Lionel Richie (Universal) proved to be iTunes' most popular artist, appearing 59 times all told, for an average of 1.475 times per possible playlist (or TPP, an objective measure reflecting the fact that iTunes-purchased songs were available to iTunes during creation of 40 playlists while CD-ripped songs could only have appeared on 20 playlists).

Red Hot Chili Peppers and The Veronicas tied for second place (55 times / 1.375 TPP) with Keane and Robbie Williams (53/1.325 TPP), Eskimo Joe (52/1.3 TPP), Good Charlotte (51/1.275 TPP) and Grinspoon (50/1.25) all appearing at least 50 times in our playlists. Looking further down the list, however, a curious trend appeared. Artists whose five songs were bought from iTunes were consistently more likely to appear on the random playlists than those whose songs were ripped from CD. Each of the top 15 artists, by number of songs played and songs per playlist, was bought from iTunes; those ripped from CD were far less likely to rate.

Songs by Def Leppard, the most frequently-played artist from CD, were chosen 24 times in 20 possible playlists for a TPP of 1.2 -- but the rate of selection for other CD artists quickly dropped off: Bon Jovi (21/2 TPP), Creed (20/1 TPP), and Gloria Estefan (18/0.9 TPP) were all slightly ahead of Andrew Lloyd Webber, the Bee Gees, Dido, Erasure, Jackson Browne, Maroon 5 and Mötley Crüe, all of which were played 17 times for a TPP of 0.85.

The least frequently played artists were all those whose songs were taken from CD, with the bottom of the rung inhabited by Kate Bush (12/0.6 TPP), Anderson Bruford Wakeman Howe (11/0.55 TPP), and Christina Aguilera and Oasis (10/0.5 TPP).

When the artists with just one song were factored in, things got even more interesting. Smack That -- a current hit by Akon and Eminem -- was played 17 times, which was the mean for the artists with five songs in the iTunes Library. Its TPP was 0.425, a frequency that translates to 2.125 if treated as though there were five copies of the song (we'll call that ratio TPP5). In other words, we were 1.44 times as likely to hear Smack That than any song by Lionel Richie, even though Lionel Richie had five songs in the iTunes Library.

Also played proportionally more frequently than five-song artists were Gwen Stefani's The Sweet Escape and Hinder's Lips Of An Angel (14/1.75 TPP5), Justin Timberlake's What Goes Around/Comes Around (13/1.625 TPP5), and Daughtry's It's Not Over (12/1.5 TPP5). Beyoncé's Irreplaceable, Fall Out Boy's This Ain't A Scene, It's An Arms Race, Gym Class Heroes' Cupid's Chokehold, Nelly Furtado's Say It Right (11/1.375 TPP5) all had as many playlist appearances as songs from the Red Hot Chili Peppers and The Veronicas -- even though the latter artists should presumably have been five times more common.

Topics: apple, itunes, ipod, shuffle, random, music, songs, playlist

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Comments (91)

  • Cassandra commented on 09/12/2009 11:30

    I have a playlist of 100 songs that I created and wanted to shuffle through. I found that iTunes on both my Mac and my iPhone were playing through the same subset of songs (approximately 20). So I unchecked all of the ones it liked to shuffle through. Now, when I start playing this playlist on shuffle, it stops after one song. This is absurd. I think it is one thing to favor songs, but not to perform at all when the favored songs are removed is ridiculous.

    I need another option.

  • Ryan commented on 29/11/2009 16:13

    The problem is how you define "random". Read more into probability theory. For example, if you have 13 randomly selected people in the room, it is more than half likely that 2 of them will share a birthday. (This seems surprising, counterintuitive even, but it is true.) Additionally, there is no "random number generator" developed, so it is obvious that the program does not generate 100% random playlists.

  • robbo commented on 14/12/2009 21:35

    kinda true but I thought it was more like 22 people in a room??

  • Tommii commented on 08/11/2009 23:04

    I had a playlist of 50 songs on shuffle, there was only one song that was in the playlist twice ans surprise-surprise apple's "shuffle" feature played them back to back.

  • Fiiish commented on 03/11/2009 11:18

    I think that the random issue is not just with itunes but with the mac book pro also. I play a game called civilization 4 on a mac book pro running Mac OSX 10.5.8. I partitioned the drive and run a copy of windows to play the game. When the game starts you can choose to play music randomly from a chosen file. I play mine from an external hard drive with a music folder. As long as the game continues the music seems random, but if you reload the game the same same band begins almost every time. For about a year every reload played Jethro Tull, and now its on a jefferson Airplane series. Not only that but if you reload again it plays a different Jefferson Airplane song in the same order on each reload. No randomness there. I have tried shuffeling the order of the songs on the hard drive with no change. If I play the game with the hard drive on any other pc the music is totally random. I even had a friend bring over his hard drive with a similar song list and the mac again went on its Jefferson Airplane kick. Any ideas on how to solve this would be great.

  • Fiiish commented on 03/11/2009 10:37

    I think that the random issue is not just with itunes but with the mac book pro also. I play a game called civilization 4 on a mac book pro running Mac OSX 10.5.8. I partitioned the drive and run a copy of windows to play the game. When the game starts you can choose to play music randomly from a chosen file. I play mine from an external hard drive with a music folder. As long as the game continues the music seems random, but if you reload the game the same same band begins almost every time. For about a year every reload played Jethro Tull, and now its on a jefferson Airplane series. Not only that but if you reload again it plays a different Jefferson Airplane song in the same order on each reload. No randomness there. I have tried shuffeling the order of the songs on the hard drive with no change. If I play the game with the hard drive on any other pc the music is totally random. I even had a friend bring over his hard drive with a similar song list and the mac again went on its Jefferson Airplane kick. Any ideas on how to solve this would be great.

  • cereal commented on 29/10/2009 01:46

    Funkleberry - thank you! Itunes definitely repeats certain songs while skipping others forever. It's particularly noticeable if your mp3's came from albums, like most of mine did. I use iTunes for "random" shuffle almost all the time, that's the main thing it has for me over actually putting on a record on the "stereo." But it clearly is not "random" or even close. I swear I hear"Hang on to Yourself" at least once every couple days, but never any other tracks from Ziggy Stardust - ever.

    I have never bought music from Apple or downloaded anything, so I doubt I'm playing many files that have been secretly programmed by Apple to repeat more as per terms of some contract with EMI or whoever. I also don't think Apple is benefitting from me hearing Aphex Twin instead of The Byrds; but perhaps iTunes has a HAL-9000 mentality, and is trying to convert me to techno. Well, it wasn't working, and now thanks to Mr. Funkleberry, I don't have to worry about it.

    Half hour into this new "playlist" and I'm hearing songs that have not been played in probably forever. Both bad and good, but at least - clearly more random.

    Hartelijke bedankt/merci mille fois/thanks ever so much!

  • Steph commented on 11/10/2009 14:59

    I've noticed this too.
    when ever i randomize my playlists the same artist are played: Taylor Swift, Cobra Starship, Flo-Rida, Kanye West and P!nk. and other artist that are famous right now.
    These artist are all in the itunes 200 right now and my itunes keeps playing their songs.
    So i believe what this article has reserched.

  • Aaron802 commented on 03/10/2009 15:11

    I did an experiment to test randomness with iTunes smart playlists. I created 26 2-second mp3 files and titled them "A", "B", "C",...,"Z" with the same genre "test1". Then I made a Helper playlist: genre="test1" select 15 items by least recently played. Then I made the Main playlist to pick from the Helper playlist and select 15 items at random. My thinking is that when a song plays on the Main playlist, it also falls off the the Helper playlist until 11 more songs have played then it makes it back on the Helper playlist. At which point, the Main playlist has a 1/15 chance of picking that song again to put back in it's lineup. What I found was no randomness at all. After letting the songs all play through, both playlists became exactly alike with the same sequence of songs. The Main playlist picked songs in the exact order they appears in the Helper playlist. Even with manual shuffling and manually playing songs out of order, both list eventually became the same. Please someone tell me my error and why this doesn't work.

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