MIDI - a Beginner's guide
What is MIDI? (Music Instrument Device Interface)
I've often heard people say, "Maybe I should get a MIDI." MIDI is not a thing you buy, its realy just a protocol or format kinda like html or spdif or something like that.
You buy things that support MIDI. Like if you buy a keyboard now-a-days it will almost certainly support MIDI output and input. What that means is:
1. The keyboard can be played via MIDI messages from an external source, like a computer program or other keyboard.
2. The keyboard can send MIDI messages out to another device enabling you to play "keyboard sounds" not on your keyboard.
The way it works is via MIDI messages. The most common MIDI message is a note. A note simply tells the pitch that is to be played, how long to hold it, how loud it is, and other stuff. If you connect a MIDI synth module ( a box that has keyboard sounds on it) to your keyboard via a MIDI cable your keyboard sends these note messages to the synth module. The synth receives the messages and plays the notes using whatever instrument it has loaded. The way the note sounds completely depends on the synth and how it decides to handle the information it received.
This is why having a good synth becomes so important. Your sounds is COMPLETELY dependent on that. One reason MIDI gets a bad name is the default synth both Mac and PCs use is VERY outdated and horrible sounding. If you play the same MIDI data using professional software or gear it will sound MUCH better :)
This is also why conversion from .MID to .WAV is not a simple straight forward task. The .MID file only contains MIDI data. It doesn't actually have any audio data to convert. It's all abstract. The best way to convert MIDI to Wav is to play the MIDI file through a synth (preferably a good one), record the output into a wave editor or multitrack recorder, and save as a wave file.
So I've touched on two different concepts of MIDI now. One is the MIDI message system and the other is the MIDI file format. For writing new music now-a-days you should be most concerned with the MIDI message system concept. Let's go over that first in a little more detail and I'll describe what it means to me in my own work.
MIDI Messages, how to use them to create your music
So if you have any experience using programs like Cubase or Sonar you know that you can create two main types of tracks:
MIDI or Audio
You create audio tracks when you want to record something in from a real source like a guitar or microphone.
You create MIDI tracks when you want to record notes to be played back by a synthesizer.
The synthesizer can be a plugin, another program, an external keyboard
, or external synth module.
The advantage of MIDI is you can change and move the notes around very easily in an editor and not have to rerecord anything.
You could create an audio track and just record the actual sound of your keyboard in, but that's already rendered out and if you want to change a note you pretty much have to go in an record the whole thing over again.
The advantage of audio is that is already rendered and doesn't need a synth to be loaded or configured to sound right. It's also less taxing on a system to play a rendered audio track than it is to play a MIDI track that often is rendering everything note by note. Let me explain more clearly:
When you play a midi track and it has many notes, most of the time it is actually like play an audio track for every single note you play. This is true if your synth is "wave based" meaning it has a recording (sample) of an instrument playing that note. To play a chord (more than one note at the same time) it has to play a sample of each note.
So to save my computer from choking in large projects, I will often try to finalize some of the heavier MIDI tracks and record them into audio tracks. Then I can unload that synth which saves memory and CPU processing power.
MIDI Keyboards, what to buy?
So for a MIDI newbie who wants to start recording a common question is "What should I buy?". Well there are lots of options depending on how much you want to spend and your goals.
As for MIDI keyboards there are several different types you should be aware of:
Consumer Portable keyboards:
These are the most common for newbies to have. They are the ones sold at stores like Wal-Mart and Fred Meyer. The have speakers built in and usually have roughly 200 sounds on board. They also usually have preprogrammed beats and accompaniments. Some have learning programs that light up keys and teach you new songs. Some of the better types of this keyboard can be very convenient for small local performances
. I've hauled my Casio out before just because I didn't want to mess with a bunch of pro gear when all I was going to do was tinkle on some keys in the background of a small religious function or something like that. These keyboards are getting better all the time and can be just fine for performing. They also usually have MIDI out so you can use them as a basic controller keyboard as well.
MIDI controller keyboards:
Really, there's two subclasses with in this genre but let me explain the basics first. A MIDI controller keyboard is a keyboard that's main purpose is to play sounds on another device like a computer or synth module. The keyboard itself doesn't generate any noise on its own at all, if they do it's very limited. MIDI controllers range from little tiny things that are pretty cheap to buy all the way up to massive full sized monsters with weighted keys and gobs of little knobs and sliders for doing cool tricks with your synths. The point is you already have sounds somewhere else that you want to use and don't want to spend money on something with new sounds that you will never use. YOu just want something good at sening out MIDI messages. You can order these online or buy them at local music stores. Now-a-days if I was starting out with a goal of only recording music on my computer (no live playing) I would consider this kind of keyboard. So many of the best MIDI synthesizers are now software based...
These like the MIDI controllers also have no speakers attached but do generate sound. You have to use audio cables to direct the sound to wherever you want it to go. Usually you send it to your soundcard or multitrack recorder or something like that and play out of your system's speakers. If you are playing live you could send to a keyboard amp or just go straight into the mixing board. These keyboards have a completely different purpose than the portable keyboards. You won't usually find the pre-programmed beats, light up keys, or auto-accompaniment features. In place of those features you gain the ability to really edit the sounds you play out of the synth. Sometimes there will be a fully functional sequencer onboard. A sequencer is a program that basically lets you write a song using MIDI messages and play it back. So using some of these keyboards you could write and produce an entire track and record it into your computer.
Back when I first started buying professional gear this class of keyboard was really the most economical way to go. I spent a gob of money on my K2500, but I didn't need a lot of gear because the K2500 can do just about ANYTHING. Now-a-days much of my K2500's functionality goes unused because it is a heck of a lot easier to do things using my computer. It would practically be just a giant MIDI controller except there are still sounds on it I like to use in my recordings.
These vary in size but are usually fairly sizable. They are basically meant to replace an acoustic piano in your home. They can be quite pricey too. This is actually the only class of keyboard that I have never bought one of. I'd honestly rather get a real piano. Digital pianos do have their advantages though, they can often play a few different sounds besides basic piano. Nothing like the 200 sounds you see in the portable keyboards or workstations. Usually a digial piano will have like 4-15 really high quality sounds on it. IE Piano, Electric Piano, Organ, and Harpsichord. Often they will have some basic drum beats built in as well. Other than that they are just big nice looking\sounding digital pianos. Again...IMHO....just get a real piano. It's gonna sound\feel so much better and the price difference really isn't that big. I used to work at a music store that survived on digital piano sales alone. In fact that store went out of business when it lost its license to sell the pianos!
General MIDI and MIDI files.
Ok on to the MIDI file. I explained a bit earlier but really want I want to dig into here is the concept of "General MIDI" or just "GM"
. General MIDI like MIDI is another thing that has gained a bad rep unjustly. This is the same problem once again. The MIDI synth used in Mac and PCs is very outdated. That synth is a GM synth.
What GM is is a specification of standard instruments for a synth to have. A MIDI file that you would typically find on the internet is a GM MIDI file. This means the MIDI file assumes the synth that it is sending data to has General MIDI instruments to play. So instrument number 1 is a piano,
49 is strings, etc. (Here's a WIKI on it If you played that same MIDI file using a synth that was current and had nice sounds it would sound a LOT better. Not all MIDI files are GM MIDI files though. You typically wouldn't distribute a non GM MIDI file though because a non GM MIDI file requires the synth you used when you wrote the MIDI file. I probably shouldn't have even brought that up :) Most of the time if you are working with MIDI on non GM synths you are saving your projects in your apps own format, IE a Cubase or Sonar project.