Let's start with a
little general information about MIDI. In the late 70s there was a problem that
musical equipment from different manufacturers had compatibility issues. Dave
Smith of Sequential Circuits, Inc. and the major musical equipment manufacturers developed the standard in the early 80s
to make musical equipment more compatible.
What does MIDI stand
MIDI stands for Musical
Instrument Digital Interface and is a standard protocol of information
interchange between electronic instruments, computers and other equipment.
How does MIDI work?
First thing to
understand is that MIDI is not sound. MIDI works by sending data signals between
equipment, not audio signals. These signals are also known as "events".
We'll get into how this
works technically later on, let's just take a simple example:
You hook up your MIDI
keyboard to your recording studio computer which has MIDI sequencer software
installed. Your sequencer software uses a software instrument plugin, which can
be a piano, sampler or any other instrument really.
When you press a key on your keyboard, the information about the key press is
sent from your keyboard, through the MIDI cable to your computer. This
information contains which key is pressed, how hard (velocity),
how long, and when you release the key. If you, while doing this,
also touch the pitch bend or mod wheel, this information is sent along as MIDI
controller data. More information is sent as well, but the ones mentioned are
the most important to know about in basic MIDI recording.
This information is picked up by the
sequencer software and recorded onto tracks. You can have any software
instrument or sampler assigned to these tracks and the software will make them
sound according to the information sent from your
The good thing about this is that once recorded in your software all this
information can be edited again and again. You can for example adjust velocity,
move notes in pitch and time, add and subtract notes by pointing and clicking,
or even assign an entirely different instrument to the track. See the advantages
of MIDI recording?
If this had been an audio recording you wouldn't have had the same opportunities
of editing and would probably have had to do the take again if you needed to
change something. MIDI files (the tracks stored after being recorded) also take
up just a fraction of the space of an audio file.
If you want to use the sounds of your own hardware synthesizer keyboard in your
recording you can simply connect your keyboards analog audio output to the line
input of your sound card and play the MIDI track(s) back through your keyboard
and into your recording software to an audio track. If you set this up with
multiple tracks on different MIDI channels (more on MIDI channels further down
the page), you could record an orchestra of up to 16 pieces all on your own with
just your keyboard. Sounds cool eh?
To take full advantage of MIDI recording it requires good quality recording
instrument plugins of course.
This was a very simple explanation. A way of how MIDI works. Enough to get you
started on the basics. There's much more to it though, so keep reading, but now
you see how this provides a very easy and cost efficient way of recording
You don't need
several synthesizers and keyboards for different styles and sounds, as you
can use the same MIDI keyboard for all the software instruments
You can dust
off that old keyboard you have and put it to good use (it doesn't need to
sound good it just needs to be MIDI compatible)
MIDI can be edited in any way you like.
MIDI equipment connect
with each other through connectors and ports. There are 3 ports available in a
standard MIDI system. That is the MIDI IN, MIDI OUT and MIDI THRU.
The MIDI IN
port is used to receive data
OUT port is used to send data
THRU port is used to pass on data in a chain of devices (also known as
What's a MIDI interface
and do you need one?
A MIDI interface is a
piece of equipment that allows the MIDI controller (keyboard) to communicate
with your computer. A standalone MIDI interface was more common some years ago
than it is today.
have this interface built in today. You will have to check though as this is
quite important. Your equipment will not work together without it.
equipment to your computer
For a newbie this might
seem as something very difficult to accomplish but it really isn't. If you have
a keyboard with a built in USB MIDI Interface it is very simple. Just connect to
the USB port on the computer and you're good to go, no worries about MIDI INs
If you have a keyboard
with MIDI IN and OUT ports you need to connect the MIDI OUT on your keyboard to
the MIDI IN port on your sound card or MIDI interface. Then you are set to
record MIDI onto your computer. If you plan on using the sounds on your keyboard
synthesizer (playing back MIDI data to your keyboard), you need to connect the
MIDI OUT on your interface to the MIDI IN on your keyboard as well.
For this connection you
If you would like to
connect more than one MIDI keyboard to your computer simultaneously you can
"daisy chain" them with the MIDI THRU port (check that your equipment have these
ports, not all do) by connecting the MIDI THRU port of the first keyboard to the
MIDI IN port of the next and so on throughout the chain.
MIDI equipment can
communicate with each other along different routes (through the same cable
though), known as channels.
You can compare this to
your TV set. Different channel numbers receive different TV stations.
There are 16 MIDI
channels altogether in common MIDI devices (keyboards, MIDI modules). If you set
your recording software track to receive MIDI on channel 1, it will receive on
channel 1 only and ignore all the other channels. So it is important that your
controller (keyboard) is sending on the same channel or else your software will
fail to record it. You also have the option to set the recording software track
to Omni reception, meaning that it will record all incoming MIDI channels.
channels to different tracks
Here we're down to the
core usage of MIDI channels. Remember that 16 piece orchestra I was talking
about earlier? Let's take a simpler example.
Let's say you have
recorded 4 instruments on 4 different tracks. Then you can assign a separate
MIDI channel to each of those tracks corresponding to the channels in your
hardware MIDI keyboard.
Now when you play back
the tracks your keyboard will play all the tracks together using all the
different instrument sounds.
If this sounds good and
you want to record it, then you can just add an audio track to your recording
software, connect your keyboard analog outputs to your sound card line inputs,
play back the MIDI tracks and record it as audio at the same time.
General MIDI or GM is
something you'll be likely to come across working with sequencers and synths. GM
is a common standard developed within the MIDI system. It's a standard where
each program number refer to the same instrument no matter what kind of keyboard
or synthesizer you use.
For instance, program
number 1 in a GM system always refer to the acoustic piano, and program 41 to
the violin. Click here for
the full list of general midi programs and more info.
MIDI (and Audio)
You have set up your rig
correctly, and you're about to start recording with your keyboard controller.
You start playing, but something's wrong. The sound you hear is lagging. It
takes up to several seconds from you press a key on your keyboard until your
software reacts and plays the sound. What is this?
You guessed right. It's
latency and it can be a big pain when you're first starting out and don't know
what to do about it.
Latency, by definition,
is the time it takes from key press until audible sound. This time will vary
greatly depending on your sound card and sound card drivers, operating system,
recording software and computer power (cpu power and ram).
In a digital recording
system there will always be some degree of latency, but there's a difference
between 5 milliseconds (virtually nothing, you can't notice) and, in worst case,
a second or more.
Sound cards, latency
and ASIO drivers
Let me tell you right
now. If you're using an older SoundBlaster Live sound card and expect to do some
efficient recording you will be somewhat disappointed. The latency on these
cards are dreadful, mainly because of the drivers. If you really have no choice
but to use this or similar sound cards check out the
Sound cards capable of
low latency recording and playback use ASIO drivers. These drivers are
especially developed for making your music equipment communicate efficiently
with your recording software through your sound card. One important thing to
notice is that you can't use these drivers in just any setting. Both your sound
card and your recording software have to support them.
Examples of sound cards
with ASIO support are:
Delta 1010LT 24-Bit 96kHz PCI Card
1616M PCI Digital Audio System
Examples of recording
software with ASIO support are:
Cakewalk SONAR Producer Recording Software (Windows)
Steinberg Cubase 4 Recording Software (Macintosh and Windows)
Live Music Production Software (Macintosh and Windows)
I will frequently
update this page and add more information on MIDI keyboards, controllers,
sequencer software and MIDI recording.