Can you name a piece of software that uses this scheme? Or, better still, the OG software that used it. If I steal this, I'd like to have something to call it. (I've seen this scheme before: I think it might be used by the keyboard built into the Squeak image that comes with Scratch 1.4.)
renoise use that convention https://files.renoise.com/manual/Renoise%20User%20Manual.pdf (page 38). I used psycle modular music in 1999 and I know that it was not the first tracker-like software to use that convention but it's as far as my memory goes.
FL Studio (fka Fruity Loops) uses this layout, or something very close to it.
The earliest I've used was Protracker, which was the most popular tracker in the early heyday of the format (late 80s - early 90s), but the earlier Soundtracker was the OG "tracker", and probably used the same layout, but I'm not sure. https://www.exotica.org.uk/wiki/Soundtracker_History
But if FL Studio (formerly FruityLoops) and Renoise use the same layout, as others have said, then those are probably going to resonate with a wider modern audience :D Or maybe just call it "FL Studio / Renoise / tracker layout"?
I don't do computer keyboard note entry any more, but I still have the muscle memory for that 4-row layout from hours spent with it in the late 90s :D And I'd totally use it in your game. (My MIDI keyboards are kinda too far away from the mouse and monitor.)