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PrometheusG5

macrumors member
Original poster
Jun 23, 2004
84
0
San Francisco, CA
What kind of formula or algorithm does iTunes use for the "Shuffle" function? I seem to get any thing but random results. Does it key off the song's rating, how many times, its played...?
 

wrldwzrd89

macrumors G5
Jun 6, 2003
12,110
77
Solon, OH
PrometheusG5 said:
What kind of formula or algorithm does iTunes use for the "Shuffle" function? I seem to get any thing but random results. Does it key off the song's rating, how many times, its played...?
I wouldn't expect anyone to know this...it's an Apple secret.
 

pdpfilms

macrumors 68020
Jun 29, 2004
2,382
1
Vermontana
I seem to get any thing but random results.

I aggree. I have 7400 songs and tend to get the same 100 songs or so when i put it on shuffle. Happens on my iPod too... but it's not to say i'm not overly satisfied with either product.
 

ephramz

macrumors member
Jan 14, 2004
55
0
I had to delve into the workings of iTunes Shuffle when I was stuck for a month with "only" about 15 GB of music on an external hard drive to listen to in iTunes. I set it to Shuffle and noticed that I kept hearing the same songs over and over, especially when I disconnected the external hard disk which I did every few days.

I soon realized that iTunes reshuffled the playlist every time i remounted the external drive. So to make sure I actually heard every song once before starting over, I did a Shuffle, then "Copy to play order" to preserve that one shuffle. Then everytime I reconnected the drive for some annoying reason it would start over at the first song again. So I'd go back in the "Most recently played" smart playlist and see where it'd left off, and jump to that song to pick up the same shuffle list again. That way I was finally hearing ALL the songs.

I still don't know what algorithm they're using, but there are several pseudorandom binary counting schemes that easily hit every song in a list once. For instance counting from 1 to 1024, but just reversing the bits of each number, will appear to jump around somewhat randomly in the list.
 

bviz2

macrumors newbie
Jul 7, 2004
19
4
San Francisco Bay Area
A few weeks/months ago I submitted an "iTunes" feedback item asking for a version of shuffle that gave a higher priority to the unplayed or least played songs. If enough people ask, maybe they will implement it.
 

PrometheusG5

macrumors member
Original poster
Jun 23, 2004
84
0
San Francisco, CA
Thom_Edwards said:
i don't know if this is what you mean, but try option-clicking the shuffle button. found that at http://www.apple.com/itunes/hottips/shortcuts.html

Not really, but it is a cool tip. It allows you to shuffle several times without going back to the original playlist, then clicking shuffle again.

However, I am still stuck with getting the same songs near the top the whole time. I wish Apple would make it more random.
 
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