Interesting emphasis on intelligent DJ mode. I have been using Groove Basin[1] as my music player for about a year now and have loved the crap out of its DJ mode ("Dynamic Mode").
The way we made it work is that every song goes into a list sorted by date last queued, and then we use a parabolic curve which means that any song could theoretically be queued next, but songs that have not been queued the longest have the greatest chance of being queued next.
This is something that is hard to test without trying it out for a long period of time, but I think after one year it is safe to say that it's a pretty damn good algorithm.
The added benefit of using "last queued date" instead of "last played date" is that if Dynamic Mode queues a song, and you skip it because you don't want to hear it, it still moves to the end of the list and becomes less likely to be queued again.
The way we made it work is that every song goes into a list sorted by date last queued, and then we use a parabolic curve which means that any song could theoretically be queued next, but songs that have not been queued the longest have the greatest chance of being queued next.
This is something that is hard to test without trying it out for a long period of time, but I think after one year it is safe to say that it's a pretty damn good algorithm.
The added benefit of using "last queued date" instead of "last played date" is that if Dynamic Mode queues a song, and you skip it because you don't want to hear it, it still moves to the end of the list and becomes less likely to be queued again.
[1]: https://github.com/superjoe30/groovebasin