What Is MIDI? The Ultimate Guide To The Most Powerful Tool In Modern Music

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When discussing all of the most impactful technical advancements in music history, what are the first things that come to mind? The invention of the compact disc in 1970? The dawn of commercial radio broadcasting in the early 20th century? The birth of the electric guitar in 1931?

While those are all certainly important, there is one invention that has skyrocketed modern music-making capabilities in a number of ways. I’m talking, of course, about MIDI (an acronym for Musical Instrument Digital Interface) which has done it’s part to alter the workflow of every music producer since its inception.

Now, I know that everyone in the world of music making has at least heard of MIDI, and most of you have probably used it. So, what is MIDI? How does it work? Why is it so important? Well, that’s what I’m here for today, to help you better  understand this revolutionary invention in order to potentially smooth out your own workflow in the studio.

Before we get too far into the nitty gritty details, let’s step back to the vibrant decade that is the 1980’s to learn about the origin story of MIDI. 

The Origins of MIDI

As you can imagine, the world of music production prior to the existence of MIDI was a little cluttered, and that’s putting it lightly. There was no standardized way to make electronic musical instruments from various manufacturers work together in harmony. In fact, it was unheard of to have a synthesizer from Korg that communicated with one from Roland.

That right there was the kicker back in the 70’s and 80’s as electronic instruments like synthesizers became more and more popular. Not only that, but these types of instruments were affordable and musicians were starting to experiment with them more heavily. 

The problem was the limitations of human anatomy itself – we only have two hands! Modulating and mapping the sounds you wanted to create on old synths had to happen in real time in most cases, and boy was this a pain in the rear.

This reality didn’t sit well with Roland founder Ikutaro Kakehashi. So, he set out to change things by first proposing the development of a new standard to Tom Oberheim, who had already created the Oberheim System. The issue Ikutaro had with the Oberheim System was its cumbersome nature, which led him to switch gears and speak to Sequential Circuits president Dave Smith.

From there, Dave Smith and his engineer Chet Wood devised a universal method of communication using Roland’s DCB as the framework. 

The initial concept was a simple one on paper. In essence, the idea was that you could have one singular “master” keyboard that generated and stored data based on what you play. That data could then be fed to a sonic generator that could turn that data into sound. 

Over time, Dave Smith, Chet Wood and even Ikutaro Kakehashi would fine-tune this idea and present it to the world at NAMM in 1983. Unsurprisingly, it was a hit and it’s gained continuous traction ever since! This creation has gone on to shape the way that electronic instruments are designed by every manufacturer worldwide. It’s become a standard, and nobody has deviated from it.

MIDI in itself is a testament to just how powerful it is when major companies work together to achieve something, not only for themselves, but for musicians everywhere.

What is MIDI Exactly?

One of the most common misconceptions that you’ll hear in regards to MIDI is that it’s a signal or even a sound source. It’s an understandable mistake, but that’s one of the reasons why I’m writing this very article.  

Think of MIDI as a vessel of information that a source signal then translates into sound. MIDI is a message that tells the audio signal what to do, and how to do it. 

Now, a MIDI message wouldn’t get very far without that audio signal that I keep talking about. Essentially, if you write out a whole complex sequence of chords on your DAW, but you don’t have any source signal attached to that MIDI event, nothing will happen.

You can also think about everything MIDI does as a language, because it kind of is. It’s a binary language of 1’s and 0’s (1’s are “note on” and 0’s are “note off”) that each source device recognizes and responds to. The wonderful thing about MIDI is that it’s a universal language, like I mentioned before.

Why Is MIDI Important?

All in all, MIDI serves as the “middle man” for all musical instruments so that everything can communicate with each other and get along. On top of that, MIDI has the seamless ability to change the source signal without affecting the MIDI messages.

A lot of folks might wonder how an invention from the 80’s still stands the test of time. How is it not obsolete?

Well there are numerous reasons for that, but a few reasons stand out above the rest:

  1. Musical parameters haven’t changed. The ways that people create music is still centered around the same formula. Notes are played, notes exist in a particular pitch, everything lives in a time signature, etc. MIDI works with these age old musical parameters perfectly.
  2. The MMA (MIDI Manufacturers Association) has done everything they can to help MIDI evolve with the times. There’s a vast array of MIDI controllers, updated manipulation and automation capabilities, as well as an ever-changing list of virtual MIDI instruments. Another example is MIDI’s ability to communicate over USB to further add to it’s universal friendliness.
  3. MIDI being a language has made it resilient to change. The world of technology ebbs and flows around MIDI, and it continues to fit right in. As long as a device speaks MIDI’s binary language, then you can use it. This is the reason why I think we’ll never see MIDI die.

My point is that MIDI is here to stay. It’s so deeply embedded in the music-making world and so many pieces of music studio equipment are equipped with it that it’s unlikely to ever see another universal language for digital instruments.

The Pros And Cons Of MIDI 1.0 

I want to briefly talk about the pros and cons of MIDI itself before diving into more technical stuff.

Here are some of the benefits of MIDI in modern-day music making:

  • Convenience – the universal nature of the MIDI protocol has allowed music to progress in some major ways. The music we all listen to today wouldn’t be possible without it.
  • Lightweight & compact – the overall size of a MIDI event (or “file” if you will) is exponentially smaller than that of an audio data file.
  • Modify and manipulate on the fly – one thing we’ll get into soon enough is the ability to manipulate MIDI messages to add even more depth to your source signal. Yet another revolutionary capability.

I know I’m making MIDI sound like it’s perfect, but it most certainly is not. Let’s talk about some of the disadvantages of MIDI in its current form:

  • Can’t be used for vocal data – vocals and audio data transmitted via microphone are a different beast entirely. The only way to create a MIDI message/event or manipulate vocal data is through a MIDI “sampler” which does lead to some interesting opportunities.
  • MIDI still only has 8-bit resolution – well that’s only true in most devices. MIDI 2.0 is slowly being rolled out, and it will offer 16 and 32-bit resolution. That being said, the majority of MIDI capable devices are still stuck in the 80’s with 8-bit resolution.
  • MIDI is a one-way street – MIDI messages/events are only accurate if the source signal is the same as the one used for production. This means that sharing projects around to other musicians relies on them using the same setup as you do.

Developers are looking to fix most of those issues with MIDI 2.0, but we’ll get into that toward the end of the article.

Different Types Of MIDI Connections

Since the dawn of MIDI, the 5-pin DIN cable has been the main form of physical connection. These are usually found on the back panel of a synthesizer or drum machine and connect to your source device through USB 3 and even ¼” or ⅛” TRS at times.

Nowadays, the standard has become USB. 5-pin DIN cables are still known to be the best to purests, but USB is certainly more universal with modern computers. Seeing as most producers use a DAW as their main hub for all things MIDI, it’s easy to see why USB is the most popular.


If you’re an avid hardware user, then learning about these ports is essential. Say you have a chain of MIDI devices that you want to flow to your source signal. How the heck do you get everything to work in sync with each other?

Well, that’s where MIDI IN, MIDI OUT, and MIDI THRU come into play. Keep in mind as we move forward that MIDI information only flows in one direction per connection. 

With that, the term used here is “signal flow” and that’s the basis on which we’ll use to understand these three connectivity ports.

MIDI IN is where you’d connect an external device to your “master” device. This is done by connecting MIDI OUT to that MIDI IN port. Remember, the output of the device sending MIDI information must always be connected to the input of the “master” device that you want to receive.

I know, it’s a little confusing. To make it easier, just think of the device that you’re connecting everything to the MIDI IN port as home base. That device is where everything is being received.

Now, if you want to connect a whole slew of MIDI devices, that’s where MIDI THRU does it’s part. Simply connect one device from MIDI OUT to the MIDI THRU port on a second device, then run that second device through to the MIDI IN port of your “master” device or “home base”. 

The trick here is to set each of these three devices to their own channels so you can use them in a single stream of MIDI information.

As you can imagine, there are an endless number of ways to set up a MIDI chain. In fact, the most common MIDI setup is a very simple one: MIDI controller to DAW. Which is a perfect transition to the next topic.

MIDI Sequencers & DAWs

A MIDI sequencer’s main job is to store MIDI information and manage playback, recording, and editing of said MIDI information. Sequencers and DAWs are the main HUB of a track or song. To better understand these tools, we have to step back a little bit.

I know we’ve already had our history lesson earlier in this article, but let’s briefly talk about one more thing from the past. 

So, before we had the modern marvels that are DAWs, music producers had simple hardware sequencers for their MIDI storage and playback needs. These consisted of the Korg SQD-1 or the Roland CSQ-600, and they were very capable devices. 

Actually, many of these devices were among the first to work with MIDI and they paved the way for the more modern methods we use today.

A picture of Ableton, a very popular DAW

Enter the DAW! Digital Audio Workstations were actually born about 6 years prior to the invention of MIDI in the form of Soundstream. By the time Cubase and FL Studio came around, the dawn of true modern music production was alive.

In fact, Cubase and FL Studio both started out as hardware sequencers. Now, I have nothing bad to say about hardware sequencers. Those two options I mentioned earlier are still very much worth using today, and they work perfectly for those with a workflow that requires a hands on approach.

On the other hand, a DAW is about as all-in-one as it gets. These awesome pieces of software are capable of handling everything a hardware sequencer can on the fly. It’s a well known fact that a DAW is essentially a complex, virtual hardware sequencer.

DAWs in conjunction with MIDI give you endless possibilities. You can add, delete, manipulate, and change MIDI information on the fly or even after the information has already been set. Most of this is done through DAWs piano roll and arrangement sections.

One other thing. DAWs give you the ability to use virtual VST instruments to translate MIDI information. You can even use hardware alongside your virtual instruments. Like I said, the possibilities are incredible!

All of this is just to say that DAWs are the modern solution to every MIDI sequencing need. They are extensive and complex and able to handle everything you throw at them.

It’s also true that many MIDI controllers and synthesizers nowadays have their own onboard sequencers that further improve one’s workflow. While we’re back on the subject of MIDI hardware, it’s about time we dive into another important piece of the puzzle.

MIDI Controllers & MIDI Interfaces

Again, considering the fact that MIDI is just a language, it’s found itself existing in virtually every type of digital instrument ever conceived. Folks used to use MIDI to speak for their guitars for goodness sake. With that, all of that information needed a way to be sent to the source signal.

That’s where MIDI interfaces come in.

MIDI interfaces are just another part of a given signal flow, and they’ve become an integral part of any producers studio setup. They give a producer the ability to send MIDI data from any instrument you wish, as long as they’re MIDI capable, of course. Alternatively, there are devices that exist with built-in MIDI interfaces and are streamlined for easy use: MIDI controllers.

Over the years, there have been a lot of different iterations of MIDI controllers. The most common among them are MIDI keyboards, but in recent years, drum machines and other interesting pad controllers have been gaining popularity.

MIDI controllers as a whole are a special kind of MIDI interface that can be one part instrument, and one part binary language producer. These are your all-in-one music production superstars, and they’ve done quite a lot to progress music even more.

Also, certain MIDI controllers work better with certain DAWs. For instance, some MIDI keyboards integrate with FL Studio more smoothly.

Ableton Live has their own line of pad controllers. There is even a company that makes MIDI keyboards for Ableton with seamless plug-and-play compatibility.

All of this is just to say that MIDI controllers have a plethora of amazing capabilities. You can manipulate and control even more components of a MIDI message with them. Understanding this actually leads us nicely to the next topic.

MIDI Messages

I’ve only mentioned MIDI messages and MIDI events about a hundred times thus far in this article. It seems right to go over what they are in detail because they have a major impact on how you use MIDI in your own unique way.

A MIDI event is a MIDI message that occurs at a specified time in a MIDI sequencer or DAW.

MIDI messages are the digital data transmissions, built entirely of the binary language we went over earlier, that tell electronic musical instruments what to do and how to do it at a specific time. MIDI messages mainly exist in two variations: System messages and Channel messages.

The two forms of MIDI messages have different functionalities. 

System messages are less used than Channel messages, but they transmit important information like timing clock and transport controls which are start, stop and play. Here are the main System messages that MIDI transmits:

  • Timing Clock – this message tells the signal when to play the notes in terms of time signature and syncs with the master clock of the source signal.
  • Transport – basic parameters like play, pause, stop, etc.
  • Sysex – System exclusive messages come from the manufacturer of the MIDI controller themselves, these are messages that you can’t control yourself, and generally are what make that particular device unique. For example, the Juno 106 was different from the Yamaha DX7 partly because of the different sysex messages programmed in them. Most modern DAWs handle these differing messages on their own without you even noticing.

Channel messages are more frequently used. They can transmit up to two kinds of data at one time. Let’s break down all of the messages MIDI can transmit via Channel messages:

  • Note on/off – this message tells the signal which notes need to be played based on a depress and release value.
  • Velocity – this message tells the signal how hard those notes need to be played. The harder the note is played (higher velocity) the louder it is. This is measured by gain or volume on a 0-127 scale.
  • Aftertouch – this message tells the signal how hard a key is pressed after it’s already in it’s depressed state. Aftertouch also consists of the note number message on top of the pressure value. Polyphonic aftertouch describes the pressure of multiple keys, while monophonic describes each individual key’s pressure. Aftertouch adds audio and MIDI effect functionality.
  • Control Change – changes a parameter value on the device.
  • Program Change – changes the patch number on the device.
  • Channel Pressure – similar to Aftertouch. Channel pressure messages send out one message for the entire keyboard or controller. Channel pressure is only the pressure value, not the note number. It’s a heated debate about if Channel pressure is better than Aftertouch, but the Aftertouch is more commonly seen in controllers nowadays since it also carries the note number value.

As you can see, Channel messages play a big role in how expressive you can be when using MIDI, but what about MIDI channels themselves?

MIDI Channels

MIDI channels give you the ability to coordinate and create all the pieces of a track. I mean, all of those messages and all of that information needs a place to live right? Well, they live in MIDI sequencers in a chain of MIDI channels.

Most modern DAWs lay everything out in an organized arrangement on their UI, which looks very similar to that of a hardware sequencer. Now, there are channels on one stream of MIDI data, but modern controllers and DAWs allow you to multiply that by how many ports/tracks they have. This basically means that you can have more MIDI channels than you need depending on your setup.

MIDI Sequencing & Quantization

MIDI channels are also the foundation for MIDI sequencing, which is the ability to playback all of the MIDI data stored on every channel at the same time. MIDI sequencing records your inputted data as MIDI which is typically presented in a piano roll window. Everything is graphed in a x-and-y-axis timing clock (sometimes referred to as a patch). This data is now ready for playback.

The awesome thing that happens during MIDI sequencing is a little thing called quantization. Quantizing synchronizes all the notes played in a rhythmic fashion. Oftentimes this is broken down by divisions of a whole to a 32nd note.

Quantization through MIDI is a wonderful way to fix things that sound a bit off in your song, and it can usually be done with ease. Just another testament to the flexibility and power of MIDI.

Automation & Manipulation

There’s one last thing that makes MIDI so expressive, and that is its ability to be manipulated. Certain MIDI manipulations can only be done through software like a DAW, but many MIDI controllers have a number of onboard controls that take care of this on the fly.

One example of MIDI manipulation that can only be done in a DAW is automation. Automation allows producers to change and control parameters over time in a track. Most of the best parts of modern music are achieved through the use of automation. 

The red lines are examples of automation.

In fact, any parameter you could possibly think of can be automated in a DAW. You can add some really cool effects to any song by automating filter cutoffs or LFO intensity, just to use a couple examples. The best part is that automation can be drawn in and created after the MIDI messages are laid out.

Now, let’s talk about those onboard MIDI manipulation controls that exist on most MIDI controllers. The most common among them are:

  • Pitch Bend Wheel – most keyboards will have this parameter. A pitch bend wheel works just like a guitarists bending strings in order to quickly change the pitch of the sound.
  • Modulation Wheel – think of this wheel or lever as on the fly automation. You can use this wheel to control almost any parameter, just like in a DAW. The only difference is that it has to be recorded and performed in real time.
  • Aftertouch – we went over this earlier in the MIDI messages section. Refer to that description for more information.
  • Pedals – foot pedals and sustain pedals are common additions to MIDI controllers. They are used to control parameters similar to pedals found on a physical piano.
  • Ribbon – typically seen as a string of dotted lights on a MIDI controller. You can run your finger along this “ribbon” to control any parameter you see fit.

With this level of control at your fingertips, you can see how far down the rabbit hole you can go. MIDI manipulation is where any musician’s creativity can shine. Moreover, this area of MIDI is where you can add your own personal touch to your sounds to set yourself apart from the rest.

The Future Of MIDI

We talked briefly about some of the disadvantages of MIDI 1.0 earlier. I mean after all, MIDI isn’t completely perfect. Developers are looking to really shake things up for the first time in a number of decades though, and that comes in the form of MIDI 2.0!

MIDI 1.0 has been the sole version since the 80’s, and even though I showed you some of the advancements that have been made since then, it still feels a little dated. On January 17th, 2020, the MMA (MIDI Manufacturers Association) presented MIDI 2.0 at the Winter NAMM Show in California.

Here are some of the updates in the upcoming version to look forward to:

  • Bidirectional communication – MIDI will be a two-way street! This update will make MIDI 2.0 devices auto-configure with each other instantly and seamlessly. This also means that MIDI 2.0 will be backwards compatible with MIDI 1.0, forever.
  • Higher resolution MIDI messages – finally, 16 and 32 bit resolution! This means that all MIDI information can be recognized, and re-created, at a higher fidelity.
  • Way more MIDI channels – while it’s true that multiplying MIDI ports can lead to endless channels, developers are looking to make MIDI channels themselves more streamlined, and more lightweight.
  • Per-note pitch bend – as it currently stands, MIDI controllers can only send out one single pitch bend message for the whole device. This update will simply add more flexibility to this control option.
  • Universal MIDI Packet – this format will make it easy to implement MIDI 2.0 on any digital transport like USB and even Ethernet.
  • Reduced jitter – this alongside the higher resolution improves message quality, and timing, to make everything work better together.

These are just a few of the major updates set to be rolled out over time. You can keep checking in with the MMA’s official website for updates as MIDI 2.0 progresses.

Conclusion – How Should You Use MIDI?

How you use MIDI is unique to you and your style. Everything we’ve gone through in this article is meant to show you how powerful, and expressive, MIDI can be. This is where you experiment and find your own way to make MIDI work for you.

You can use a DAW as your main hub, or a hardware sequencer. Maybe you’ll be more comfortable with VST software to create and manipulate your MIDI messages, or you’ll use them in conjunction with hardware MIDI controllers.

No matter your setup, after you’ve got everything connected, you then just start creating messages for your source signals and lay down the sounds you like. Writing music with MIDI is as open-ended as it gets, and the level of freedom you have with it is unparalleled.

You have a whole world of creativity at your fingertips, and with MIDI tools in your arsenal, the possibilities are literally endless. My only goal with this article is to give you the know-how necessary to harness the power of MIDI in your musical endeavors.

With that, I hope this article has proven helpful, and as always, feel free to reach out with any questions you may have.

Jeremy Bongiorno
I have been a musician and producer for over 15 years. My goal is to provide reliable, honest information and hopefully help to improve the quality of life in your studio.

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