What Is a MIDI Keyboard? How It Works and How to Use One

A MIDI keyboard is a piano-style keyboard that sends instructions to a computer and makes no sound of its own. When you press a key, it tells your music software which note you played and how hard. The software then plays a sound through a virtual instrument. If you have no keyboard yet, the free Audio to MIDI converter can turn a hummed tune into the same kind of note data.

How a MIDI keyboard works

MIDI stands for Musical Instrument Digital Interface. It is a language that devices use to share notes, not sound. A MIDI file or a MIDI message holds facts like "this key, started now, held for this long, played this hard."

A MIDI keyboard turns your finger presses into those facts. A plain MIDI keyboard has no speaker and no built-in sounds. You hear nothing until you connect it to something that makes sound, such as music software on your computer.

That is why one keyboard can play a grand piano, an organ, a string section and a bass in the same hour. The keyboard stays the same. Only the instrument it controls changes.

What is a MIDI device?

A MIDI device is anything that sends or receives MIDI messages. A keyboard is the best known one. Others include drum pads, controllers with knobs and faders, electronic drum kits, wind controllers and many synthesizers.

Some of these only send MIDI, some only receive it, and many do both. A sound module, for example, receives notes and makes the sound. A keyboard sends notes. A computer running music software can do either job.

What is on a MIDI keyboard

Keyboards differ a lot in what they offer, but these parts are common.

• Keys. Most have 25, 37, 49, 61 or 88 keys. A full piano has 88. Smaller ones save desk space and are easier to carry.
• Velocity sensitivity. The keys detect how hard you hit them, so soft playing sounds soft and hard playing sounds loud.
• Pitch bend and modulation. A wheel or strip next to the keys bends notes up or down, or adds vibrato to the sound.
• Knobs and faders. These can be assigned to anything in your software, such as filter cutoff or track volume.
• Pads. Square, touch-sensitive buttons for playing drums or triggering sounds.
• Sustain pedal input. A jack for a pedal that holds notes the way a piano pedal does.
• Octave buttons. They shift the whole keyboard up or down so a small one can still reach every note.

How to connect a MIDI keyboard to a computer

Most modern keyboards connect with a USB cable. The cable usually carries both the MIDI data and the power, so there is nothing else to plug in. Older gear uses a round 5-pin MIDI cable, which needs a small adapter or an audio interface with MIDI ports to reach a computer.

How to use a MIDI keyboard in a DAW

A DAW (digital audio workstation) is the program where you record and mix music. Most of them work with a MIDI keyboard in the same way.

1. Plug in the keyboard and wait a few seconds for the computer to recognize it.
2. Open your DAW and check its settings for MIDI inputs. Make sure your keyboard is listed and turned on.
3. Create a MIDI track and load a virtual instrument on it, such as a piano.
4. Arm the track for recording. Press a key and you should hear the instrument.
5. Record. Play a part, then stop. The notes appear on a grid called the piano roll, where you can fix wrong notes, move them, or change the instrument afterward.

If you press keys and hear nothing, the usual causes are a track that is not armed, the wrong input chosen in the settings, or no instrument loaded on the track.

MIDI keyboard vs digital piano vs synthesizer

These get mixed up often.

A digital piano is built for the feel and sound of a real piano. A synthesizer creates sounds with oscillators and filters. A MIDI keyboard is the cheapest way to control sounds on a computer, because the computer does the sound work.

Do you need a MIDI keyboard to make music?

No. You can draw notes into the piano roll with a mouse, or type them with your computer keyboard in many DAWs. A MIDI keyboard makes this faster, and it helps you play parts the way they feel.

There is another way to get notes into a project without a keyboard. Record yourself humming, singing or playing a guitar line, then convert the audio. Here is how that works in Unmix Studio:

1. Open the Audio to MIDI converter. It runs in your browser, so you do not sign in and nothing is uploaded.
2. Pick a type. Vocals / humming reads one note at a time. Piano / keys keeps chords.
3. Drop in a file, or press Record and play or sing straight into your microphone.
4. Watch the notes land on an 88-key piano as the recording plays.
5. Download the .mid file and drag it onto a MIDI track in your DAW.

It works best with one instrument at a time. If you only have a finished song, the MP3 to MIDI converter accepts it, and the Piano Extractor can pull out the piano first for a cleaner result.

How to choose a MIDI keyboard

• Size. Pick 25 or 49 keys for a small desk, 61 for a good balance, and 88 if you play piano seriously.
• Key feel. Try the keys if you can. Weighted keys feel like a piano. Lighter keys feel like a synth.
• Controls. Pads suit beat makers. Knobs and faders suit people who tweak sounds.
• Software that comes with it. Many keyboards ship with a basic set of instruments, which helps if you are just starting.

Start small. You can always buy a larger one once you know what you miss.

FAQ

What is a MIDI keyboard used for?

It plays virtual instruments and records notes into music software. You can use it to play piano, synth or drum sounds, write melodies and chords, and control settings with its knobs and faders.

Does a MIDI keyboard make sound?

Not by itself. It sends note data to a computer, a phone, or a sound module, and that device makes the sound. You can listen through speakers or headphones connected to the computer.

What is a MIDI board?

Most people mean a MIDI keyboard. The phrase can also describe a pad controller or a control surface with knobs and faders, since those are MIDI devices too.

Can I make MIDI without a keyboard?

Yes. Draw the notes by hand in your DAW, or record a hum or an instrument and convert it with the Audio to MIDI converter. It is free and runs in your browser.

Do I need a special cable for a MIDI keyboard?

Most current keyboards use a standard USB cable. Older ones with a 5-pin MIDI port need an adapter or an audio interface that has MIDI inputs.