Many audio interfaces do not have midi cable ins or outs. So, if I want to use my pedal board to change states in C3, I could only get a midi signal into my laptop thru usb. I assume these pedals are also made for keyboards since they have 1/4 inch plugs out to keyboard sustain. Also, many midi keyboard controllers are only being made with usb midi. I like midi cables much better than usb cables, but it seems they are slowly being phased out. I understand the hardware thing, just found it strange in this "usb" world, there wasn't a connection for it.