MIDI

MIDI is an interface for musicians http://en.wikipedia.org/wiki/Musical_Instrument_Digital_Interface. It does a good job of broadcasting what note was pressed and when it was let go. It also may tell how hard it was pressed and if the mod wheel or the pitch bend was tweaked and how much. It does tons more than that but you probably get the idea. This is important because you can now feed this info into something that produces sound, maybe a keyboard or a sound box of some kind like my Yamaha VL70m. You can record MIDI and play it back to more than one place or to a box with a variety of settings to hear what that might sound like. Also, it is sound independant, that is, MIDI has nothing to do with audio... yet. So, MIDI has to be conveyed from place to place, from your MIDI controller to a sound maker then to an amp and finally to the speaker. If you record a piano performance, there's no way to change the sound of the piano. If you record a piano performance in MIDI, you can play it on a Yamaha Grand or a Hammond Organ, it's just where you route the MIDI signal. So, you have to deal with the logistics of having three keyboards, three computers with a dozen sound-producing pieces of software or hardware like the Yamaha VL70m. Instruments have a MIDI in and a MIDI out. Many have a MIDI Thru but not all. The Thru just passes the info on. Lots of times, you want your main keyboard to go to several places and what might work better is a One In-Four Out box. If you don't have MIDI thru on something, you pretty much need to do that sort of thing. MIDI Out is what THAT piece of hardware is producing in the way of a MIDI signal. In my case, my MIDI console "black box" has two keyboards that I want to go everywhere. If I can merge them, then I am now dealing with only a single MIDI cable that I can feed into my main computer. But, I have two computers in my black box console so I bought a Midiman merge box with 2 ins and 2 outs. Now I plug my two CME keyboards into my two computers with only four short cables and this box. My computer with Real Band on it has to output MIDI too. I have a MIDI track with my harmony notes on it and I feed that into my TC Helicon Voicemaster. Other recorded tracks will be actual old-fashioned audio and will go directly to the mixer.