What is MIDI in Audio? – Important Technology!

Have you heard of “MIDI” before? If you have played around with enough electronic instruments, you will definitely come across this term at some point. In order for you to connect certain types of electronic audio devices and musical instruments, you will need to understand this vital concept. So the golden question for today is – What is MIDI in Audio?

The subject we are discussing here is a really lengthy one and will take forever if I were to cover every single detail (we don’t want that do we?). Hence, I aim to provide enough information so as to give you a decent understanding on how MIDI works in the practical world, and how it benefits music producers and composers. Let us now start learning!

Introduction – A Vital Interface

The Musical Instrument Digital Interface, or simply MIDI, is a technical standard that allows various types of electronic musical instruments, computers and audio devices to connect and communicate with each other. It comprises of a protocol, digital interface and connectors. One MIDI link can carry up to 16 channels, each of them can be routed to a separate device.

USB MIDI Keyboard

PreSonus PS49 USB MIDI keyboard / Photo by Matt Vanacoro / CC BY 2.0

A MIDI connection actually transmits control signals for parameters such as volume, vibrato, audio panning, cues, and clock signals that set and synchronize tempo between multiple devices. It also carries event messages that specify notation, pitch and velocity. A MIDI cable is used to carry these messages to other devices that control sound generation and other features.

An example of a typical MIDI setup, is the use of an electronic musical keyboard (as a MIDI controller) to trigger sounds or samples created by a synthesizer (software). This MIDI data can also be recorded into a sequencer (either hardware or software), which allows the data to be edited and also played back at a later stage of production.

Let us now take a look at the various topics that will be covered:

  • Instrument control
  • Composition
  • Sequencers
  • Notation software

    MIDI Controller

    MIDI keyboard controlling synthesizers / Photo by Blurred Ren / CC BY 2.0

Instrument Control

The main function of MIDI is to facilitate communications between musical instruments and allow one instrument to control another. Analog synthesizers without a digital component can be modified with kits that converts MIDI messages into analog control voltages. When you play a note on a MIDI instrument, a digital signal is created and can be used to trigger other instruments.

Other instrument parameters can also be remotely controlled with MIDI. Sound generators such as synthesizers, consists of various sound shaping tools. For example, filters adjust timbre, and envelopes automate the way a sound evolves over time. Effects devices also have parameters, such as delay feedback or reverb time. All of these can be attenuated remotely with MIDI.

You can save a set of adjusted parameters to a device’s internal memory as a “patch”. These patches can then be remotely triggered by MIDI program changes. A total of 128 different programs are allowed (based on the MIDI standard), but if a device’s patches are arranged into banks of 128 programs each, and combining a program change message with a bank select message, more programs can be provided.


Computer software, or hardware music workstations can also be sequenced with MIDI. You can find many digital audio workstations (DAWs) in the market, that are designed to work with MIDI as an integral component. Many of these DAWs are now developed to include MIDI piano rolls that allow recorded MIDI messages to be extensively modified.

Piano Roll

DAW piano roll

Composers can easily use these MIDI tools to audition and edit their work much more quickly and efficiently, as compared to older methods such as multi-track recording. They also allow composers to compensate for their lack of strong keyboard skills, and allow individuals without formal training to produce polished arrangements.

Since MIDI is just a set of commands that create sound, MIDI sequences can be altered in ways that prerecorded audio cannot. Musical aspects such as key, instrumentation or tempo of a MIDI arrangement can be changed, and its individual sections can be reordered as well. Being able to quickly create ideas and instantly hear them played back allows composers to experiment extensively.

Music Sequencer

A sequencing software is very beneficial to a composer or arranger as it allows recorded MIDI to be manipulated or altered just by using standard computer editing options such as cut, copy and paste and drag and drop. Universal keyboard shortcuts can also be used for smoother workflow, and editing functions are often selectable via MIDI commands.


DAW with piano roll (bottom) and sequencer (top with tracks) / Photo by SquarePusher / CC BY 3.0

Every channel in a music sequencer can be set to play a different sound, and they can also give a graphical overview of the arrangement. There’s a variety of editing tools at your disposal, including a notation display, typically used to produce printed scores for musicians. Arranging music is also made easier by tools such as looping, quantization, randomization, and transposition.

Creating beats for music is also made simple, and groove templates can be utilised to duplicate another track’s rhythmic pattern. By using real-time MIDI controllers, you can create realistic musical expressions. MIDI can also be integrated with recorded audio and video tracks, and mixed down. Your audio work can then be saved, and transferred between different computers.

Notation Software

MIDI allows notes (typically played on keyboard) to be instantly transcribed to sheet music. Unlike sequencers, notation software lack audio editing tools, and is designed to produce neat, professional printouts that are optimized for live performers. These programs provide support for dynamics and expression markings, chord and lyric display, and complex score styles.

Notation Software

“Finale” notation software / Photo by didouchk / CC BY-SA 3.0

You can also find notation software in the market that can print scores in braille (Hey, blind people can play music too!). ScoreButt is a software that can transcribe from MIDI to scores in real time. SmartScore can produce MIDI files from scanned sheet music by reversing the “MIDI to score” process. Some other notable programs include Finale, Encore and Sibelius.

There you go, the essential aspects of MIDI that every music producer or composer should know. I hope you guys will now be ready to incorporate MIDI into your audio productions!

Do leave questions or comments below, and share this article if you have learnt something!



When I'm not rocking out to great music, I'd prefer to be sleeping on a field on a windy day =)


  1. You are right, I have heard of Midi but really didn’t know what it was or used for in music. This article was very informative and easy to understand. So from reading, I gather that this is a device (actual piece of equipment) that is used to transmit control signals? This is most important when you are making music? Not just listening to it, right? Don’t laugh LOL…shows you how much I know :/

    • Hey there!

      MIDI is a digital interface (as implied by its expanded phrase) that can be implemented into any device (audio equipment), to allow it to communicate with other compatible electronic hardware. Various cables and connectors are used to transmit these “control signals” within a MIDI connection.

      Don’t worry, when I first started out, it took me a while to wrap my head around the concept of MIDI as well!

      Thanks for dropping by!

  2. Farhan, I had heard (and used) the term “midi” many times over the years, and really just had a vague idea what it meant. I didn’t even know it was an acronym, lol. But this one sentence cleared it up like crystal for me:

    “The Musical Instrument Digital Interface, or simply MIDI, is a technical standard that allows various types of electronic musical instruments, computers and audio devices to connect and communicate with each other.”

    Wow! I get it!!

    I thoroughly enjoyed an appreciated the whole artilcle. You really know your stuff, that’s obvious, and have a gift for explaining techie stuff in words that a layman can understand. I have plans to one day have an in-home recording studio (I am a lifelong musician, former professional, but I still write, play and perform now and then), so I got this post bookmarked – thanks a bunch, dude!

    • Hello Marvin!

      It really feels good to know that readers enjoy my articles and also benefit from them. Thank you for your kind compliments, and don’t hesitate to come back if you need any help setting up your home studio!


  3. I really enjoy making music with the program Fl Studio, you probably know what that program is. I wanted to learn more on MIDI, and really what it was. I was going to purchase a MIDI cable for a piano to hookup to my computer to make music more easily. Your information really made me learn a lot more about it and I am super excited now thank you!

    • Hey Nick!

      I’m glad that you got something out of this article. To know that people are inspired to make music after reading my articles, really means a lot to me. Do come back anytime!


Leave a Reply

Your email address will not be published. Required fields are marked *