Freedom of Expression

  • by Kim Bjørn

Looking at various forms of electronic music interfaces, we explore methods for interfacing with music, through hardware, software, or a combination of both. In this first installment, we cover technology and techniques for creating expression.

Musical expression is often defined as a performance with a very personal response. The human voice might be the ultimate example of this, able to mesmerize an audience with its highly expressive nature: fluid modulation of amplitude and pitch; an evocative timbre that’s intrinsically human and alive; and of course, the articulation of words, which themselves hold further meaning.

There’s a visual element to performance too. The connection between sound and its source is obvious: we can see where the sound originates from, and what effort it takes to make it. This isn’t limited to vocalists, of course. Experienced theremin players, for instance, similarly express themselves through ultra-precise microtonal notes; subtle vibrato by modulating pitch; and sudden sweeps and tremolo by manipulating volume. Carolina Eyck is one such thereminist — notice the dynamics in pitch, volume, and articulation in her performance.

Electronically created music is not always about a personal relationship. However, most producers would agree that creating expression is crucial for successful productions, whether they’re intended to move the dancefloor at a club, or move the audience at the cinema.

Now we’ll look closely at key aspects of expression, beginning with the fundamental parameters before moving on to technical goals of expression, and the technology required to achieve them.

Playing a theremin combines audio and physical expression in a very distinct way.”
– Dorit Chrysler, thereminist, composer and musician


Volume and Timbre
In contrast with the sparsely notated scores of the Baroque period, 19th Century composers started to mark intended expression and dynamics in more specific ways. Users of symphonic sample libraries are well accustomed to Italian words like Pianississimo (as soft as possible) or Fortississimo (very very loud). The dynamic markings of loudness range from ppp – pp – p – mp – mf – f – ff – fff, corresponding to a MIDI velocity level ranging from roughly 15-127.

Although electronic instruments and synthesizers offer many parameters for expressive manipulation, volume remains among the most important. When acoustic instruments are blown, bowed or struck harder, this creates a change not just in volume but also in timbre, and many electronic instruments recreate this by using MIDI velocity to modulate more than just amplitude levels. Less commonly understood is that MIDI CC 11 is dedicated to Expression, allowing musicians a further way to control playing ‘hardness’ (CC7, Volume, is related, but is intended only to control output level and not timbre — it’s more like the level fader on a mixer). Often, an expression pedal is used, which is quite different from a volume pedal, as explained in this video.

Of course, there’s more to expression in electronic instruments than just volume and velocity. Even as far back as 1928, the Ondes Martenot — one of the first popular and practical electronic instruments — offered very expressive controls for manipulating pitch, dynamics, timbre and articulation of notes. Several controls are used in combination, and the keys can move sideways, providing slight vibrato when wiggling them. The Ondomo is a modern Japanese-American recreation of this very instrument.

Technical goals of expression
In electronic instruments, we can distinguish between two overall technical reasons for using expression:

Emulation: This means mimicking the sound and playing style of an acoustic instrument, such as a guitar, saxophone, cello, or a symphony orchestra. This requires not only well-crafted software, but the hardware must offer sufficient and appropriate control over relevant parameters. Usually, that means expressive controls like keys, wheels, knobs, faders, touch-strips, etc, but could go as far as emulating the playing experience of the original instrument itself, as with a wind controller, MIDI guitar or the jog wheels on a DJ controller.

Variation: When working with synthesized sounds, a certain amount of “life” is desirable. To add interest or a sense of evolvement, techniques like layering different sounds, crossfading between layers, opening a filter, etc, become essential — especially in sustained sounds like pads, which don’t feature a characterful attack. In dance music, the most recognisable use of expression is probably the crescendo (or decrescendo) before the drop, obtained by filtering frequencies or modulating pitch.

The importance of control
Electronic instruments, as opposed to acoustic instruments, are rarely of an expressive nature. Instead, sound originates in the circuits or software, with physical or virtual controls allowing the artist to add expression by altering parameters. The more control options, the greater the capacity toward expressive results.

The legendary Yamaha CS-80 from 1976 is considered one of the most expressive analog synthesizers ever made, due in very large part to its responsive tactile controls. It features a long ribbon controller with the ability to begin bends at the first point of contact, and a keyboard with pressure sensors under each key for finely nuanced timbre control — here demonstrated by Vangelis, who used it on the first Blade Runner soundtrack. Having used the CS-80 for the soundtrack of Blade Runner 2049, composer Hans Zimmer spoke in an interview about the experience: “It responds to your touch; it translates your soul and your musicality the way a musical instrument is supposed to.”

Yamaha CS-80

Image: Perfect Circuit Audio


When soloing with synths and other electronic instruments, many of the expressive characteristics of acoustic instruments become desirable, such as manipulating the pitch more fluently than a set of “on-off” keys allow. The following iconic clip of George Duke using the “whang bar” on his Castlebar clavinet is a great example of how a single control can create a highly entertaining and expressive performance.

Expression is the name of the game in electronic music and there are many instruments that are up to the challenge. Check out PUSH TURN MOVE to dive into the depths of expressive control.

Thanks for stopping by! Join us next time as we explore both common and esoteric expressive controls found on many different types of electronic instruments.

This article was part of a blog-series originally appearing at who kindly allowed us to repurpose Kim's articles again – here in a version edited by Collin Russel.


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