The Tera player currently uses an algorithm that does not create evenly distributed random playback. After a lot of experimentation some of us came up with a system that adjusts for the algorithm on the Tera and creates perfectly even selection of songs in random play.
Note added: There is word that Charles has updated the algorithm used in more recent Tera players. You can probably check with him to see if your unit has the new algorithm. If a Tera is using the newer algorithm, then the instructions below become irrelevant. The new algorithm by itself should do a pretty good job of playing music randomly.
Here is a new set of rules that work at every level on the Tera (root, artist and album) to create perfectly random selection of songs:
1-If there are 1-4 folders or tracks in a particular folder, then add exactly 4 empty folders to that folder, and use numbers (00001, 00002, 00003...00010, 00011, etc.) to name the empty folders so they come before all other folders/tracks (this rule for numbering empty folders applies to all of the following rules).
2-If there are 5-8 folders or tracks in a a particular folder, then add exactly 8 empty folders.
3-If there are 9-16 folders or tracks, then add exactly 16 empty folders
4-If there are 17-32 folders or tracks, then add exactly 32 empty folders
5-If there are 33-64 folders or tracks, then add exactly 64 empty folders
6-If you have more than 64 folders or tracks at any level, then it is best to rearrange your music so that you have 64 or less at each level. This is because Tera is limited to 128 folders/files so you cannot add 128 blank folders to a folder with 65-128 real folders.
NOTE: You can stop here. If you just apply the first 6 rules to every folder on your card including the root folder, then you will experience a huge improvement in the randomness on the Tera...probably 90% of the possible improvement. The last two rules are only important if you want perfectly random playback of every song on the card.
7-For perfect randomness, all folders at the same level of organization should be in the same range: i.e. all artist folders should have either 1-4, 5-8, 9-16, 16-32 or 32-64 real album folders, and all album folders should have either 1-4, 5-8, 9-16, 16-32, or 32-64 real songs. Do not combine ranges at the same level. It is OK to have different ranges at different levels: i.e the root folder can have 32-64 artist folders in it and then all artist folders can have 1-4 album folders in them and that will still work. I would suggest dividing the folders/tracks in any folders with unusually high numbers of folders/tracks to bring them down to the range you plan to use at that level. Again this rule only matters if you want the randomness to be perfectly distributed across all of the songs.
8-Exception to rule 7: If your folders on the same level have contents that cross two of the lower ranges, then you can just use the higher range's number of empty folders. For example, if you have album folders with a wide range of say 3-16 tracks, then just add 16 empty folders to all album folders, and all of the tracks will have the same odds of playing. Or if instead you happen to have just a few very large albums with more than 16 tracks, then again I would suggest you divide them into two or more smaller album folders with 16 or less tracks each to bring them more in range with the other albums on your card.
If you play with the spreadsheet here (created by Suicidal_Orange), you will see that these rules always create a perfectly even selection of all of the "real" folders and also all of the "real" tracks at each level on your card. However, again I will point out that to have perfectly even randomness, you need to stay in the same range for all folders at each level: root, artist and album. You do not need to understand the mechanics, but if you follow the rules above and keep each level in the same range (i.e. all artist folders have say 1-4 real album folders and therefore 4 empty folders, and all album folders have say 9-16 real tracks and therefore 16 empty folders) then the randomness will be perfectly even throughout your card. Or just follow rules 1-6 and the randomness will be pretty much even across the whole card with only a few slight exceptions - the randomness will still be something like 90% better overall than it would be without adding empty folders at all.
A couple of extra notes:
1-The root folder can have any number of real artist folders (except above 64) as it does not have to be similar to another root folder, because obviously there is only one root folder. Once you add the correct number of blank folders to the root folder, then all artist folders will be selected evenly in randomness. (And it may be obvious, but if there is only one artist folder in the root, then no need to add any empties, but for 2 or more artist folders, follow the rules above.)
2-When using blank folders as place holders, they should be named/numbered as follows 00001,00002,00003...00010,00011,00012, etc, so that they are sure to be arranged before any other folders/tracks on the card. This works as long as none of your tracks have a name that starts with more than 3 numbers. Note that the Tera does not always see folder names in the order your computer sees them so a song that is named "03-name of song" may appear before a folder named 00004 on your computer but not on the Tera.
3-Having all of these blank folders in there does not seem to increase the time between tracks. The Tera seems to just keep very rapidly selecting until it finds a song, and it does not seem to take any longer than it used to between tracks (except maybe very occassionally, it will take a little longer to select a song).
4-The extra folders also do not seem to interfere with ordinary navigation. When you skip to the next artist folder or album folder using the navigation buttons, the Tera just skips to the next real folder. In other words, you never need to manually skip through 16 or 32 blank folders to get to the next one.
5- It speeds all of this up if you create 16 or 32 blank and properly numbered folders in a folder on your computer's desktop. Then you can copy and paste the blank folders as needed into each folder on your card. It would obviously take a lot longer to manually create 16 or 32 new folders one at a time in each folder on your card, and since you may need to add the same large number of empty folders to lots of folders, copy and paste is definitely the way to go.
6-I used to think the first folder had to have a song in it for the Tera to start playing, but with empty folders instead of short silent tracks (which I tried first) as place holders, the Tera just skips ahead to the first folder with a song in it.
7- Avoid having real tracks mixed with real folders at any level, as this will mean those tracks will be selected much more often than the tracks in one of the folders. Best to stick with the Artist/Album/Track system of organization like that in iTunes so that all the actual WAV file songs are in an album folder, and to avoid having WAVs in your root folder or in an artist folder.
I will report that with my card setup according to these rules, I am now hearing lots of songs I have not heard in a very long time. I have been skipping through a lot of music to see if I can see any patterns, and so far I can't sense any pattern or emphasis on certain music. I also have not experienced any repeats of songs that I have already heard that same day or the day before which used to happen often (up to 7 or 8 times in a single listening session) before I figured this stuff out. It really seems now like I have a card with 2500 songs on it, instead of seeming like a card with 200-300 very familiar songs on it. Of course the old familiar songs still come up, but I would say they are maybe one in ten of the songs I hear which is about right. After all, they are part of the random selection process along with all of the music I used to hear less often.
Maybe we can call these the Rube Goldberg Rules for Randomness. Let me know how they work for you. And a big thank you to Suicidal_Orange. It was his spreadsheet that allowed me to figure out an approach that works without having to have an exactly even number of songs or albums in all folders, or other awkward limitations.
Edited by Nirmalanow - 5/1/14 at 6:23pm