Basics of MIDI and MIDI Controllers | Home Recording Basics

You’ve now set up and acoustically treated your studio. You’ve tracked drums, bass, guitar, and vocals. But you still feel like something’s missing. Maybe an orchestral symphony? A five-piece horn section from New Orleans? How about a vintage analog electric piano? With MIDI, anything is possible.

MIDI stands for Music Instrument Digital Interface, and MIDI controllers come in all shapes and sizes. Some are just pieces of plastic—think Guitar Hero controllers—while others are highly sophisticated machines created to emulate the experience of playing a grand piano, high-level synthesis, and modern drum machine technology all in one.

But regardless of build, they all have one thing in common: none of them actually make any noise.

MIDI controllers are just that—controllers. They’re used to control plugins to create music. The controllers themselves don’t actually produce any sound—just data that your computer turns into sound.

Without a computer, a MIDI controller really is just a piece of plastic. But with the right plugins, your MIDI controller can be Alicia Keys’ piano at Madison Square Garden or Hans Zimmer’s orchestra at the Sydney Opera House or Dave Grohl’s drum kit at Sound City Studios. MIDI can be any sound imaginable, and even some that aren’t.

MIDI Controllers

There are literally hundreds of MIDI controllers available on the market. What makes any of them different from the last?

Size: MIDI controllers are usually categorized by how many keys they have. Some controllers have no keys and are intended for beat makers. Some mobile controllers have only a dozen or so keys. Most keyboards, though, fall into the 25-, 49-, 61-, or 88-key variety.

Feel: Fully weighted keys are designed to recreate the touch and feel of playing a grand piano. Ivory keys attached to weighted hammers have a certain affect on your play style, and these keyboards aim to emulate that. Unweighted keys are much less sensitive to touch, while semi-weighted keys are a budget-conscious compromise between the two.

Pads: In addition to emulating a piano, MIDI controllers are also used as drum machines. Some models don’t include any pads, while others include up to 64. The weight of the pads varies, too, and has an effect on the sensitivity.

Bells and Whistles: MIDI controllers are designed to improve your workflow. Some controllers are designed like synthesizers with rotary knobs and mod wheels for real-time program changes. Others are designed more like consoles and come with transport controls and faders.

Budget: At the end of the day, it all comes down to how much you have to spend. A lot of MIDI controllers offer great bang for your buck. Do some research, and find the right MIDI controller for you.

If you’re a musician looking for a way to record full piano pieces with string accompaniment, maybe you should look for something with 88 fully weighted keys and skip out on the pads and knobs. But if you’re a producer looking for something to make beats with, maybe lose the keys altogether and get something with a bunch of pads.

Virtual Instruments

Now that you’ve picked a MIDI controller, you need something to control. Virtual instruments are plugins that act as sound modules and create tones that you can manipulate. They can simulate vintage equipment, emulate signature sounds, or create something entirely new.

You can use virtual instruments to see what a part might sound like if it were played on a piano, a trumpet, and a violin, all with the click of a button.

If there are hundreds of MIDI controllers available, then there are probably thousands of virtual instruments, each with their own unique sounds."

If there are hundreds of MIDI controllers available, then there are probably thousands of virtual instruments, each with their own unique sounds. Most DAWs come with stock virtual instrument plugins, so there’s no need to break the bank if you’re just trying to lay down some ideas. That said, some virtual instruments cost thousands of dollars.

Professional songwriters often choose to spend the money on high-end virtual instrument emulations rather than routinely pay for musicians and studio time, but you can achieve pretty realistic results with some of the more affordable plugins, too.

Editing MIDI

The best part about MIDI is that you can edit it very easily. Say you nailed the solo in the bridge, but you missed one note. With MIDI, you can just correct the wrong note after the fact. Or maybe you can end it early for a drum fill. No problem, just adjust the timing in the editor!

The basics of MIDI are actually pretty simple. You can change everything about the notes being played, their velocity, and any modulation using your DAW.

Everything—notes on the keyboard, velocity, and modulation—is assigned a value from 0-127.

Notes: You can select any note on the theoretical keyboard from A0-C8, and change it any time. You can also change the start and end time of the note.

Velocity: Velocity is basically how hard you hit the key. As always, values range from 0-127. Velocity actually has a huge effect on how “real" or “robotic" something sounds. If every note is the same velocity, there’s no rhythm, no groove, no life.

Pitch Bend: Most MIDI keyboards have a pitch bend wheel, which can be used to gradually increase or decrease the pitch of a note.

Controllers: Some of the more advanced controllers feature Mod Wheels, Foot Controls, and Sustain / Expression pedals, which all have their own unique effect on different MIDI patches. Every option on your controller should be adjustable in your DAW.

One piece of advice before you head down the rabbit hole is don’t get lost. It’s easy to spend hours tweaking knobs and testing presets without actually making any music. Just remember, a MIDI controller is a tool to help you create and improve your workflow.

Learn more about how to record music at home on our Basics of Home Recording homepage.