QWERTY keyboard as a musical instrument versus a piano

It struck me that most all pianos are demonically pricy, but most computer keyboards have more than 88 keys themselves.
A lot of music programs map the keys so that they somewhat approximate the white/black piano key pattern for midi entry,
but have you seen other interesting ways of treating a computer keyboard as a live instrument unto itself?

Weirdly, I come across more maestros of musical calculators than of QWERTY keyboards...
https://www.youtube.com/watch?v=ZLr8ntnL__A

Not as a live instrument but trackers use the keyboard in a couple of different ways - typing in hexadecimal code for certain events or in something like Renoise instead of just having the ASD row act as white keys they'll fit 2+ octaves using more rows.

That's funny that you would bring renoise up -- I did actually use it as a live instrument that way!
I get why they do the layout that way but they're letting a bunch of keys lie fallow...

Keyboard Pioneer:
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnAR-NSnEzdjtZwbpdj3wcP-94xhP-7ce7VDS8_Lf6WAedwu8QyiRA_h6yIQihEcQdI_teUYhENn7ZYtpnt8dxq6hrm8I3RUkSLW4RUxVOtID0xJmz0WEq7lmxyDePyafhxI3bTcILI7Gm/s320/Steve_Wozniak.jpg