The first of an occasional series of experimental techniques and ideas. To kick off we look at a way of combining drum machines and noise gates to produce unusual rhythm patterns and textures.

On many occasions in the past I have had cause to reiterate that it's not necessarily good equipment that makes good music, but good ideas. Having said that, I do find that new or unusual sounds and techniques can help the jaded composer to get out of a rut and lead to new avenues of exploration. This was most powerfully demonstrated to me when I bought one of the first Roland guitar synths and all the new sounds at my fingertips led me in all kinds of interesting directions that I would never have considered if I were playing, an acoustic guitar for example.

Listening to the radio often reminds me just how deep a rut popular music has dug for itself and no rut is deeper than the almost total lack of interesting rhythms or rhythm sounds. Before you all write in to complain, I must add that there are of course a few welcome exceptions. One might ask why programmable rhythm machines are considered necessary when all you hear is the same beat often at the same speed. I suspect a preset only model would be more than satisfactory for these requirements and the currently accepted drum sound differs little from the old Linn type sounds with the odd spot of gated reverb thrown in. Well, so much for negativity... what can we do about it?

I'm not going to advocate that you should write songs in odd time signatures because much of the record buying public like to be able to tap their feet without getting them tied up in knots, but if you are working with a drum machine and you have a noise gate, there are one or two interesting tricks that you could try to inspire new ideas. In order to put these ideas into practice you will need a programmable drum machine that gives you the facility to programme at least one external trigger output, and a noise gate with attack and release controls as well as an external key input.

Configuration

Only one wiring configuration is necessary to get things rolling and that is shown in Figure 1. The drum machine's output is simply fed into your mixer in the usual way but the external trigger output is fed to the key input of the noise gate. If you now consider the unlikely piece of programming where you have a snare drum beat on the first beat of each bar and trigger-outs on the other three, you will hear only one drum beat per bar but the gate will be opened three times on the remaining three beats. So far we haven't specified an input for the gate so there will not be any sound. If however we feed in a steady drone from a synth, this will be audible when the gate opens and so will form a rhythmic pulse. Figure 2 should make this clear. The shape of the pulse depends on the settings of the gate's attack and release controls and if you have a hold time control, this can be brought into play too. In this way, you can use the gate controls as an envelope shaper to give you a percussive sound, a simple burst or even a bowed sound by using a slower attack.

In Practice

Used with a more practical rhythm pattern, this simple trick can help to create a tight, compulsive backing track (and might even replace a bass instrument) and, if you have a 'floor' control on your gate, you can use this to allow a little of your input tone to be mixed into the output even when the gate is closed. If your gate doesn't stretch to a floor control, you can get the same effect by splitting the signal feeding the gate and putting a small amount of it through a spare mixer channel. This way the tone will always be present but will be accented where you have programmed your trigger outs.

"...you will need a programmable drum machine that gives you the facility to program at least one external trigger output, and a noise gate with attack and release controls as well as an external key input."

But what happens now if we remove the steady musical tone and replace it with something like a filtered noise sound with a slow VCF sweep? Well, now we get the bursts of noise rather than tone but the sound will be different for each beat due to the effect of the filter sweep and because the gate is closed most of the time, the filter sweep will not be heard as such and so the tonal changes will appear to be random, almost like a sample and hold effect. The next step might be to replace the tone input by something quite different such as a tape loop (part of one of your other songs for example) or maybe even a mic stuck in front of 'Eastenders', if you're into that kind of thing. (Isn't everybody? — Production Ed).

A further refinement might be to split the gate output and feed one part via a delay device into a spare mixer channel. By carefully setting the delay time so that the echoes fall between the beats, the overall rhythm may be enhanced. Panning the echoes to one side with the original gate output panned to the other side also adds interest.

And There's More

If you have a 2-channel gate, try getting both channels to trigger together by splitting the key input. Don't put the gate into stereo mode or this will defeat the object. Now set the attack and release times differently on the two gates and pan the resulting outputs left and right. This way you will get an interesting image shift on each beat, the character of which will depend on exactly how the attack and release times are set.

An alternative input for the gate (or gates) is afforded by a digital reverb unit (spring units are unlikely to have a long enough decay time) fed from one of the drum machine outputs and set to a long decay. By setting the gate controls to give a short decaying reverb burst on each programmed beat, the effect of a drum sound followed by several reverb decays is created. An interesting variation is to replace the reverb device by a delay unit fed from the drum machine. A long delay time with lots of feedback will generate a very cluttered sound, but when this is chopped into bursts by means of the gate, it can create some very worthwhile rhythmic effects.

The Final Frontier

The purpose of this rather general piece is to inspire experimentation, not to instruct in specifics. The results obtainable from this simple combination of commonplace studio equipment are incredibly varied; you can patch in other effects, select new sound sources and program any rhythm pattern you like. Every result will be different. Imagine a dance-like beat accompanied by gated, harmonised vacuum cleaner or 16 to the bar of The Dagenham Girl Pipers played in reverse... the possibilities are endless.