Fer,

Ever see one of those movies where there's an old "player piano" in one scene? Essentially, it involved a roll of paper which had holes punched into it which, when run over a set of pins, would tell the piano which key to play. So, voila, look ma, no hands and no piano player.

Basically, MIDI is simply an electronic version of the player piano.

Obviously, it's much more sophisticated. It stands for Musical Instrument Digital Interface. Think of it as digital code that can be transmitted between MIDI-compatible instruments (keyboards, drum or synth modules etc), devices (like effects units) and/or computers to tell the receiving instrument which key to play, which controller to adjust, which patch to load, which and how much of an effect to add. MIDI software can also detect signals coming from drum pads and other types of triggers (like the keys on your keyboard) so it can receive and interpret as well (velocity etc).

On it's own, without an external device or soft synth, MIDI doesn't generate sounds, it just sends instructions. Just like the paper scroll from the player piano couldn't generate sounds unless you loaded it into a piano.

So when somebody says they are going to "record something in MIDI", what they're saying is that they are going to play a keyboard, hit a drum pad or whatever and the MIDI software is going to "remember" (record) the events. The advantage being that once the "events" are recorded you can play them back repeatedly and send the instructions back out to a different device
or sound each time until you get the sound you want. Using the analogy of the old player piano, you are simply punching holes in the scroll of paper so that you can take the scroll to a different piano and play it back as often as you like. You just have to make sure that the piano you take it to is also a player piano and uses the same type of scroll. Fortunately for us, everybody in the industry was willing to adopt the same kind of paper scroll (MIDI code) and make it the standard.

Plus you can manipulate what was "recorded" just by changing the instructions. Don't like the key you played something in? No problem, just use your MIDI software to go through the events it recorded and move them up or down. Screw up on the timing? No problem just get the software to "quantize" everything and move it to the proper place in the bar. Want to send what you played to a friend? Great, you can just send the MIDI file (.MID postfix usually) without having to send a huge WAV or some audio format. Of course, your friend will need to have some means (ie MIDI software and a midi-compatible playback instrument/device) to hear what you played since all he'll have are which notes were played when with which settings, patch etc.

So big a topic, so little time. Hope this helped.

thank you very much for the time spent in answering. it´s a big help, I appreciate it