MIDI Controllers & How To Use Them: Part 1

Synthesized music need not lack expression; with the array of MIDI controllers at your disposal, you can add a whole new dimension to your music. In this short series, Nick Magnus explains how...

The accusation must have been made more times than anyone cares to recall: that electronic music lacks feel, is soulless, has no character and no dynamics. These 'truths' have been especially rife since the advent of MIDI and sequencing, with the quantisation, automation and repeatable performances that became possible as a result of recording music into a computer. It has rarely been stated, on the other hand, that a cathedral organ is soulless, characterless or lacking in dynamics, despite the fact that it is simply a machine, no more or less than any synthesizer. That instrument comes to life at the hands of those organists who have learned control of the beast using all four limbs (and who knows what else) to operate pedals and switches provided for the very purpose of expression.

MIDI keyboards, too, are provided with pedals and switches, or inputs for such items. Unlike the organist, who only has dedicated controls at his disposal, we are usually given the luxury of choice in the function of those provided to us. Depending upon the software of the receiving synth, we can choose for a pedal to affect a number of aspects of performance. The traditional organist has more knobs, and excepting the most elaborate of instruments, can define none of them. So if this potential for synthesizer control is there for the taking, why do the negative accusations persist? One could guess that it is possibly due to technophobia — or the problem could be more fundamental: just what do you do with those controllers, and how? Might all those Yamaha VL1s merely end up sounding like so many £4000 Stylophones?

To help motivate synthesists out of this rut, I would like to share some of my basic, meat‑and‑potatoes (lentils‑and‑rice for veggies) uses of MIDI controllers, together with one or two specialities I've discovered over the years. Some of these are very easy to do, and will certainly add a new dimension to many sounds. One or two will require a little practice to master — but then that's in the nature of learning any skill.

Volume (CC#7)

This is perhaps the most basic controller, offering continuously variable dynamics (unlike key velocity, where the level remains nominally static after a key is depressed). A typical use of CC#7 would be to add a natural ebb and flow to strings and pads. All too often, one hears such sounds simply start, exist and stop. Real strings have a 'phraseology', including a controlled start, some light and shade, and a controlled fade to silence. Individual note velocities can be used to highlight specific lines within a part, while the volume messages control the overall intensity and mood. The advantages of recording into a sequencer become clear; you can overdub these control messages after the performance has been perfected. This applies to most of these examples.

Manually performed envelopes can be created with great precision, particularly when the sequencer's tempo is reduced. Anyone familiar with bands of the '70s, such as Yes, will remember the wonderfully gothic strains of Mellotron choir chords swelling up from nothing and ending abruptly as if a radio had been switched off. This can be achieved effortlessly using a MIDI volume swell, followed by a CC#7 value of zero at the vital moment. Love it...

It follows, then, that we have at our disposal an ideal dynamic mix automation system built into the very equipment we're using. But what of 'real life' instruments recorded to tape? MIDI‑automated VCA devices exist to cope with this, also using volume messages, but owners of the Korg Wavestation A/D might not know that the two audio input jacks on that instrument will also respond to CC#7. Any two tracks or subgroups from tape can be sent into these, routed to two unused A/D outputs and have their levels automated just like the MIDI tracks.

Modulation (CC#1)

In its usual guise, modulation is used to control LFO depth, for effects like pitch vibrato. But CC#1 is a continuous controller like any other, and vibrato can be applied by other methods, such as aftertouch. Since most synths respond to CC#1, and can have various functions assigned to respond to it, this controller becomes an ideal vehicle for other forms of expression. Assigning filter cutoff and/or resonance to respond to the modulation wheel makes basic but effective (recordable) timbral changes possible. It's even better if you can simultaneously assign VCA level to the same wheel; this enables imitative sounds to have a natural tonal change in sync with the volume variations. Try utilising this technique to breathe life into an oboe patch or to simulate dynamic brass swells. The difference is striking. Any other available continuous controller can be used in this way if your synth will respond to it.

Breath Control (CC#2)

This is one of the most useful controllers, and possibly one of the least used by keyboardists. Assignable in exactly the same way as modulation, it provides an extremely natural method of articulating notes using blowing and tonguing techniques (stop that smutty giggling, Wiggins Minor). If, as in the previous example, it controls filter and volume together, any 'blown' or legato instrument comes to life in a remarkable way. There are two principal problems:

1. Not everyone has access to an input from a breath controller

2. Co‑ordinating hands and mouth in blissful harmony takes a little practice. (WIGGINS!! See me afterwards).

Problem 1 can be solved in two or three ways: MIDI‑merge the breath control data from a suitably equipped Yamaha DX7, WX7, KX5 or similar (more on the KX5 next month), or purchase an Anatek pocket breath control pedal, which has the necessary BC input. If your synth won't respond to CC#2, use either of the above in conjunction with the real‑time transform page of your sequencer to turn the breath data into something your synth responds to. Figure 1 shows a typical setup. The solution to problem 2 is quite straightforward... plenty of punishment and self denial.

Combining breath control with modulation or aftertouch is even more fruitful. Assign the mod wheel/aftertouch to pitch vibrato (with maybe even a little VCA and VCF mod) and then, if your synth allows, make the LFO speed vary slightly depending on the mod depth. The deeper the mod, the faster the vibrato. This varying modulation, together with the detailed articulation, should convince even hardened cynics that electronic sounds are anything but lifeless.

Channel Aftertouch

Channel Aftertouch is usually best suited to triggering LFO functions, as opposed to continuous effects such as filter sweep. The problem with using this controller for filter movements is that the filter value drops to zero as soon as a key is released, producing discontinuities in the movement. One way around this is to assign the sound to a restricted zone on the keyboard (say, all but the lowest note) and add the aftertouch by applying smooth pressure changes on the blank key. Overdubbing aftertouch in this way is also an option.

Polyphonic Aftertouch

Polyphonic Aftertouch is used to apply an effect (pitch bend, LFO, etc) to individual notes within a chord. Accurate control of this is not easy in a live performance and, like Channel Aftertouch, is achieved most easily as an overdub. This requires playing the note in question before going into record, keeping it held until the appropriate moment then applying pressure to the key. If the sound is a sustained one, this may be cacophonic to say the least! Expect to make more than one attempt.

Cyclic Pan (CC#10)

This trick, although a little fiddly, can produce the illusion of sounds that rotate on a horizontal plane in front of the listener. Using both pan and volume messages, it involves creating controller templates within a sequence that are copied and overlaid onto the music. The idea is to create a regular panning movement which is ghosted by identical volume messages 90 degrees out of sync. As the sound pans left, the volume is at maximum in the central position. As it pans right, the volume is at its minimum in the centre, giving the impression of the sound moving toward and away from the listener. If you're feeling adventurous, try assigning the filter to the volume messages, so that the sound is at its brightest when loud, and dullest when quiet. Those of you who are one step ahead will have realised that if CC#10 is also made to cause a tiny amount of pitch variation to one oscillator of a two‑oscillator sound, this can create a mock doppler effect, provided that the highest pitch (in this case pan right) is followed by the highest volume. You guessed it — a fake Leslie! Figure 2 illustrates how this can work. It's necessary to make only one controller template for pan and pitch; the one for volume/filter can be ghosted from it, with the ghost track being suitably time‑shifted into position.

Next month I shall be filling your datastream with more useful tips, including the use of a certain hardware controller which, for me, has become quite indispensable.