I play the lumatone (https://www.lumatone.io/) which is very similar.
I personally love it, especially as I like to do a lot of improv in various tunings, and the layout makes transposing and thinking about structure so much easier than a traditional keyboard. The terpstra seems similar, not sure what their selling point is over the lumatone.
Edit: oh, it seems that the lumatone is the commercialized version essentially. Great hardware, can reccomend!
> oh, it seems that the lumatone is the commercialized version essentially
From the same makers or others?
On the website I can find no info whether this project is concluded or not.
have you ever tried a midi fighter? https://www.midifighter.com/ if so how do they compare?
I would expect the midi fighter with less keys would be somehow easier to control and get better results from.
Any idea why something like this costs $5,000? It seems like manufacturing costs would justify 1/10th of that maybe? Disclaimer: I'm not a hardware manufacturer nor retailer, I'm just going off what regular typing keyboards go for.