Alex wants to upgrade his Mac and attach it to a MIDI keyboard to make music. He wants to be able to tether it, not rely on a network or wifi connection. Leo says that macOS doesn't support touch, so he'd have to use a simulated mouse. But it's doable. Leo would recommend going with a Thunderbolt connection in order to do it. The chatroom says that there's a Mac Compatible touchscreen Monitor on sale at Amazon. Leo says, though, that he could use an iPad for that function as well and get the touchscreen option. He can connect it via USB and run the Mac that way.