Basic MIDI Setup

This is a basic modern MIDI setup when using a computer sequencer and several MIDI instruments.

What is a hardware MIDI setup?

In this paragraph we intend to tell you the basics of a modern hardware MIDI setup with multiple instruments and a computer. A MIDI setup includes MIDI controller, a computer running a sequencer (it could be Apple Logic Pro X, Ableton Live, Steinberg Cubase, Cockos Reaper, MOTU Digital Performer, Avid/Digidesign Pro Tools, Renoise, Bitwig Studio, FL Studio, BandLab Cakewalk, Opcode Vision, Voyetra Digital Orchestrator Pro or Sequencer Gold Plus, Passport Master Tracks Pro), a thru box, and several MIDI instruments. The MIDI instruments could be synthesizers (either keyboards or sound modules), samplers, or drum machine. Most common MIDI signals are MIDI note on and note off signals. Each signal specifies a MIDI note number between 0 and 127. When a MIDI note on signal is received by a MIDI instrument, it plays a sound. When it receives a MIDI note off signal, it can start to end the playing of a sound. The MIDI interface connects a computer to a MIDI instrument. A MIDI interface can have one MIDI out, which can be connected to the input of a MIDI thru box, and the MIDI single split to each instrument, all receiving the same signal. Sequencer tracks are each assigned a MIDI channel. The MIDI instruments can be set to only respond with a sound when a note is received for the channel it is assigned. The audio outputs of each instrument are sent to a mixer where they can be mixed, sent to speakers or headphones, recorded to individual tracks or to a stereo mix. Now we'll get into more details.

What is MIDI?

MIDI stands for Musical Instrument Digital Interface and it was a standard agreed to between Roland, Yamaha and Oberheim in 1983. The first MIDI synthesizers were the Roland Jupiter 6 and the Sequential Circuits Prophet 600. They were demonstrated together, able to play each other's notes at The NAMM show in 1983. MIDI connectors are a 5 pin DIN jacks on the back of MIDI compatible equipment. They are connected together with MIDI cables, a 5 pin DIN connector is on each end of the cable. All MIDI instruments that produce sounds have a MIDI In. By definition must all MIDI instruments that make sounds (synth, sampler, drum machine) must have a MIDI input. And MIDI controller, all of which must have a MIDI out, can control any MIDI instrument by transmitting MIDI note messages to a MIDI instrument. Some MIDI controllers that have integrated USB MIDI interfaces and may not need a MIDI DIN connector. In this case, if the controller is to be connected to the computer with USB, an additional MIDI interface is required to get a MIDI DIN output connected to the other instruments in the setup.

What is a MIDI instrument and what types are there?

There are 6 basic categories of MIDI instrument.

A MIDI controller is a device used to send control signals in the form of MIDI data to other MIDI-compatible devices, such as synthesizers, samplers, and software instruments. It serves as the main user interface for the musician, allowing them to input musical information and adjust various parameters. Unlike a synthesizer keyboard, a MIDI controller does not generate its own sounds, it only transmits MIDI messages for controlling other MIDI devices. The main feature is the piano keys. Some also feature pitch bend, modulation wheel, and additional sliders to control what are known as MIDI continuous controllers.

A synthesizer keyboard combines a keyboard controller with sound generation capabilities. It has built-in sounds and can produce a wide range of sounds and tones. Similar to a sound module, a synthesizer keyboard can also respond to MIDI signals on different MIDI channels. The MIDI channel determines which specific sound or patch will be played on the synthesizer keyboard. Through the Local on/off control, a keyboard synthesizer can have the internal keyboard and synthesizer disconnected from each other. Local On means the keyboard controls the synthesizer. Local off means that keyboard is now just a MIDI controller, sending out MIDI messages from its MIDI output when notes are played, and at the same time the synthesizer will respond to MIDI note messages coming into the MIDI input.

A sound module is a device that generates and produces various sounds, but only via a MIDI input from keyboard controllers or sequencers. A sound module is like the keyboard synthesizer mention above but doesn't have any kind of keyboard for playing notes by hand. It receives MIDI signals on specific MIDI channels. A multitimbral sound module or synthesizer keyboard can respond to more than one MIDI channel. The number of channels it can respond to are called parts. An 8 part multitimbral sound module can respond to 8 different MIDI channels at the same time, as long as it does not run out of voices, which is another limitation of a synthesizer based on its hardware capabilities. A synthesizer that only responds to one MIDI channel at a time is referred to as monotimbral. Sound models can be rackmount or table top from factor.

A sampler is a device or software that captures and plays back recorded sounds, often referred to as samples. These samples can be recordings of real instruments, vocals, or any other sound source. With MIDI, a sampler can be triggered to play specific samples in response to MIDI note-on signals. By assigning different MIDI channels to various samples or instruments within the sampler, it can play different sounds based on the MIDI signals it receives. A sampler can also be multitimbral, but early samplers were monotimbral.

A drum machine is a device or software designed specifically for creating drum and percussion sounds. It usually includes a sequencer for programming drum patterns and a sound engine that generates the drum sounds. Like the other devices mentioned, a drum machine can also respond to MIDI signals, usually on MIDI channel 10 (a conventional agreement made by many producers and manufacturers). Different drum sounds are assigned to various MIDI notes. Most drum machines adhere to the General MIDI note number assignment so that when switching from kits, a similar sound can be heard. A drum sound module is just like a drum machine, but it has no sequencer. Drum machines and drum sound modules are typically monotimbral.

An effects processor is a unit that can put effects on a sound such as a reverb, echo (delay), distortion, flange, phase, chorus. etc. MIDI program change can be sent to an effects unit to change effects at a specific point in a song, or it can receive MIDI CC (continuous control) data to change an effects parameter. They can also receive sysex data to receive new effects programs that can be saved to their patch memory. They do not respond to note data. It is technically not an instrument but some effects units do have midi inputs to receive the data and outputs to send sysex patch data.

In a typical MIDI setup, a sound module might be set to MIDI channel 1, where MIDI note signals from a sequencer or controller set to channel 1 will trigger the sounds within the module. The synthesizer keyboard could be set to MIDI channel 5, so MIDI note signals from a controller or sequencer set to channel 5 would play different sounds or patches on the keyboard. The same would be true for a sampler or drum machine. By assigning different MIDI channels to these devices, it allows for precise control and coordination when playing or sequencing multiple instruments together in a MIDI setup.

Details of a Typical Modern Hardware MIDI Setup

The components and configuration of a typical modern hardware MIDI setup are a computer, a MIDI interface, a MIDI thru box, keyboard controller, along with some sound modules, synthesizers, samplers, or drum machines.

MIDI Channels

Each MIDI 5 pin din plug can carry up to 16 channels. Typically, each channel is a assigned to a patch. In the sequencer, each track is also assigned to a channel.

MIDI Signals and Note On/Off

The most common MIDI signal is MIDI note on and note off data. These signals are used to trigger sounds in MIDI instruments, with each signal also specifying a MIDI note number ranging from 0 to 127 and a velocity between 0 and 127. The MIDI note on starts the sound and the MIDI note off starts to end this sound. An example of "starting to end" a sound would be for a synthesizer patch will long sustain. The sound may sustain after the not off message has been received. Inversely, a patch with a long attack might not be heard immediately after the note on message is received.

MIDI Sequencer

A MIDI sequencer is a device or software application that is used to record, edit, and play back MIDI data. It allows musicians and producers to create and arrange musical compositions using multiple tracks that will output MIDI notes and other control data over the course of the song. MIDI channels are assigned to a specific sequencer track. A list of midi sequencer software can be found above in the first paragraph. Some sequencer apps that started out with only midi later added digital audio tracks which would make them DAWs + sequencers.


A digital audio workstation or DAW is multitrack digital audio recorder and track mixer and some also feature a MIDI sequencer along with hosting for virtual instruments (which also receive MIDI). Current DAWS are Apple Logic Pro X, Ableton Live, Steinberg Cubase, Cockos Reaper, MOTU Digital Performer, Avid/Digidesign Pro Tools, Renoise, Bitwig Studio and FL Studio.

MIDI Thru Box

A MIDI thru box distributes a MIDI signals to multiple instruments. It sends the same data to each output, but since each instrument can be set up to respond only to specific MIDI channel, the instrument can ignore the other channels. It is possible to do thur-in-thru-in-thru-in, etc daisy chains with MIDI cables and devices. However, potential latency introduced when the daisy chain is more than a few devices long. This is where a MIDI thru boxes would be useful since it does not have this latency.

MIDI Interface

A MIDI interface is a hardware device that serves as a bridge between MIDI devices, such as keyboards, synthesizers, and drum machines, and a computer sequencer. It facilitates the exchange of MIDI data between these devices and the computer. Modern MIDI interface typically connects to the computer via USB ports and provides both MIDI input and output connections for connecting MIDI devices. When a MIDI device sends MIDI data, such as note-on/off messages or control changes, the MIDI interface converts and relays the data to the computer sequencer. Similarly, when the sequencer sends MIDI data, the interface translates it into a format that MIDI devices can understand and sends it to the connected devices for playback or control. This way, the MIDI interface enables seamless communication between MIDI devices and the computer sequencer, allowing for recording, playback, and manipulation of MIDI data in the production or performance process. A MIDI interface can have an integrated thru box, where each MIDI out sends the same MIDI data, on all channels. MIDI interfaces with numbered outputs can be addressed independently in the sequencer, allowing for more than 16 MIDI channels in a single setup.