Machine Communication: Using and Understanding MIDI

andrewheermans

Devices, Multimodal Writing, Tools

A single chair surrounded by a mass of electronic instruments.

When multi-track recording was developed in 1955, it allowed for the concept of “production” as we understand the term in contemporary music-terminology. By recording the individual elements of a performance, one could alter and edit each part of the whole composition, or start from individual parts and construct an entire composition. This not only changed the musical process, but the product as well, unlocking new and previously impossible feats of musical arrangement and production.

On a smaller scale, the development of MIDI technology not only created the material conditions for new forms of musical production and output, but the quality of these conditions informed the cultivation of specific attitudes about what music is and how one goes about making it.

Standardized in 1983, MIDI (short for Musical Instrument Digital Interface) carries event messages between musical devices through a proprietary cable-port. The connections allow for messages that specify notation, pitch, velocity, parameter messages, and clock signals between devices. MIDI information is strong and clear, and can be transferred through up to sixteen channels before decaying. This means that a network of up to sixteen devices can be in communication, in a variety of different ways. For example, you can have a MIDI keyboard sending note and velocity information to a synthesizer, and the synthesizer will generate the keystroke information through its own source. Or you could have a sequencer based synthesizer control the the clock (start/stop) and tempo of a drum machine, and have the drum machine send the Master (where the midi signal path begins) synthesizer’s sequence into another sound source, and so on.

In other words, the development of MIDI technology allows machines to communicate with one another through a universal language, and cooperate with one another. This allows musicians to develop personalized networks of communication between machines, in whatever way caters to the creative needs or wants of the user. In an abstracted sense it is a “Seven Bridges of Konigsberg” graphical solution to the problem of musical timing and human imperfection, where the “absolutes” of musical propriety are systematized and re-articulated through mathematically precise machine-logic. In another sense MIDI dis-articulates the musical act itself from the quality of the sound produced, and has helped usher in the era of “presets”.

What does it look like to engage and experiment with MIDI connections, to construct a specific informational flow that puts multiple disparate units in concert together?

Here is a fairly simple MIDI implementation I set up to have a synchronized “one-man band” of drum machines and synthesizers:

This is an Image of multiple electronic instruments connected through MIDI connections. The signal begins from a Yellow drum machine, and travels into blue synthesizer, then into a red drum machine, and finally into a smaller, gold mini-synthesizer. All the machines in the chain of connections receive "clock" information (the Beats per minute) from their Master unit, and some of the machines receive note information as well. What happens is that all the machines will start and stop at the same click of a button, allowing for synchronized improvisation.

Here is a quick breakdown of how the connections work in the image:

1. The Yellow Drum machine is the master clock and begins the signal path. It sends the clock information (the tempo setting) to every machine on the path, and additionally sends the note information from one of its six analogue voices through the red and blue machines, into the smaller golden synthesizer. This means that a sequence that originates in the drum machine is sent to the synthesizer to dictate what notes will play. The units that are MIDI connected, an thus capable of strictly functioning as sound modules for incoming note information through MIDI, are called “slave units” in the nomenclature, while the originating or first machine in the signal path is the “master unit”. (The human/machine rhetoric inherent in such nomenclature is its own topic worthy of consideration, but will be used here since the aim of this post is to introduce MIDI as it is used and understood my musicians.)

2. All machines used her run their sequences through a quantized, sixteen-step grid that can be expanded in multiples of 16. I have 32 step sequences running on the yellow and blue machines, while the other machines cycle through sixteen steps only. This can layer in complexity and produce an effect of constant flow or change within the sequences. I have the golden synth playing its MIDI information through a 5 step sequence, which places it in a different time signature, and so the synth lines will drift in and out of sync, which creates an effect within the patterns of “human imperfection”, where timing is not always perfect.

3. The two machines on the bottom are not connected through MIDI, and simply receive the clock information in a more rudimentary fashion, through electric pulses sent through an auxiliary cord that bind the machine to the same tempo as the master unit. This means that these machines do not start/stop in unison with the others, and that the machines cannot operate as sound modules for another sequencer, they must be programmed on their own.

Here is a brief video that demonstrates MIDI in action. Everything in the video except the connections themselves are improvised, I set up the rig of machines in a certain way, and let them communicate in their own ways, slowly adding complexity to the repeating sequences through parameter changes or real-time programming.

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