A very minor quibble with the Every PC that can play sound will also have a mic input.

This is not necessarily an absolute truth. Most PCs that can play sound probably will have a mic input, but some with "motherboard" integral soundcards may not. It's not something that's really common, but it does happen.

Off the issue at hand perhaps, but many more PCs that have pretty good soundcards, whether "integral" using chips on the motherboard, or plugin cards, have omitted the MIDI jack to make room for multiple speaker jacks, and in some cases the alternative of using the "joystick" port with an adapter doesn't work because of mouse conflicts. Sometimes one can switch to a USB or IR mouse to free the serial (joystick/mouse) port to get a MIDI device to hook up, but it can be a hassle.

Most PCs that have a "real" soundcard will have at least one mic input; but beware of the exceptions - which are NOT necessarily "spec'd" in the description of the new machine you're about to buy.

John