midi keyboard scanning

I have a korg microkey midi keyboard that i want to connect to mozzi library (or possible make my own sythesizer with an stm32 instead). The problem is that the midi out is in USB style, and seems pretty difficult to have a usb host microcontroller that can interface with it. So i thought i would scan the keys directly (i have some experience with this as i made my own typing keyboard). Here is the tricky bit: there are 61 velocity sensitive keys = 122 actual switches in the matrix, there is only 16 wires coming from the keybed, 122 switches would require a minimum of 11 + 11 wires. Anyone know what kind of trick the original board is doing to scan the keys?

Are there any electronics in the keyboard?
Otherwise it could be charlyplexing to do the scanning like in this link:-

You need a schematic to be sure.