The video Sebas just posted might explain it but I don’t have time to watch the whole thing right now, but for the NEI thing, I believe it’s like this:
NEI trig evaluates true if the “most recent” trig expression on the neighboring track was true. The neighboring track is actually the previous track sequentially, so if you’re on track 4, the NEI track is track 3.
I don’t believe the neighboring track’s trigger has to be on the most recent step… it could be from 5 steps ago or whatever, as long as whatever the most recent expression was, evaluated to true.
As far as uses… I think you just have to get creative with it
I assume it’s more for experimental kind of stuff, I don’t know if there’s an obvious use for it in more traditional songwriting approaches.
One way I can think of, is let’s say you have an extra snare hit on a 33% trig. But when that snare triggers, some other sound on another track (well, it would have to be the very next track, or you would have to rearrange your tracks to do this) that normally happens right after it or something, sounds too cluttered. So you could use the !NEI (the reverse NEI), so that when that snare does trigger, this other sound WON’T trigger, to keep things clean. Following that setup, you could even add another trig with that same sound, but more delayed, and set that to NEI. So you still get the same sound but at a different time, when that 33% snare triggers.
I’m no expert and there are probably some really creative ways to use it, but that’s what I have thought about in my short few weeks with the Digitakt so far.
I’m not sure if there is much use combining it with a neighbor trig that is on a set repeat amount like 1:2, 2:4, etc. Because you could just set your trig to that same repeat amount and it would come out the same. Unless you want to set off a chain of stuff that is going to share the same repeat value, but want to be able to control it with only one trig maybe? But in general I suspect the NEI is better used in conjunction with random chance trigs… so that when the random stuff does happen, you still have some control over what “other stuff” happens at that same time