Take away the time-keeping function of a drum pattern and you've got a rhythmic catastrophe, right? wrong, you've got this month's beatbox programming feature.

One of the most attractive aspects of South American and African music for me is the fact that rhythm is seldom employed simply as a time-keeping device - as it is in so much Western music. As should have become clear during our investigation of rhythmic form from both these parts of the world, it occupies a far more pivotal role in the structure of the music, and more often than not, has a marked influence on the harmonic and melodic considerations of a given song.

This realisation led me to consider just what could be achieved using contemporary rhythm programming methods if the constraint of time-keeping was removed. This isn't to suggest I was interested in producing rhythm patterns designed to be replayed at fluctuating tempi (although I might be tempted to look into it before this series is through). Rather, I simply decided to find out what could be achieved if the usual timekeeping reference points in a pattern (bass and snare drums and hi-hats) were given a less prominent role - or a different function altogether.

I also decided that I had to achieve my objectives without recourse to rhythms which were in any way ethnic in origin (I concede that The Beat has, at times, begun to appear like a WOMAD-sponsored section of MT). And although I did allow myself the use of a number of instruments (primarily Latin) which could be described as "ethnic", few, if any, would be outside the usual array of voices found on most current machines.

In many ways, I suppose you could describe these as the kind of rhythms which drummers ought to play when unaccompanied, but seldom do. Having said that, however, like many patterns we've looked at in this series, most of these examples would prove difficult, if not impossible, for one person to play on conventional instruments. Indeed, the more elaborate patterns would, I think, prove taxing for a drummer and a full percussion section.

Anyway, the fruits of my labours can be seen in Patterns 1 to 7 and "experienced" with the aid of a couple of fingers and moderately well-equipped drum machine. More than most rhythms, these patterns lend themselves to experimentation and positively cry out for individual interpretation. Remember, their primary purpose is to sound good in their own right; though they can obviously be used as rhythm tracks within a song or piece of music, they are intended to take centre stage and not be compromised in any way by other instruments - quite the reverse, in fact.

As usual, space prevents me from including variations on each pattern, but this is what you should be striving to achieve - perhaps chaining a number of them together to provide a rhythm which shifts around a central axis. This can be achieved by naming certain instruments as the static elements of the pattern and others as being more "nomadic".

As ever, the choice is yours, but bear in mind the cyclical feel of these patterns and the different role of the bass and snare drums.

The highly eclectic nature of all seven patterns precludes a detailed description of any one of them (the way I see it, if you can program them, you can categorise them). But don't forget how much variation can be achieved simply by using drier, tighter sounds or heavy, more ambient ones - or combining the two. This is particularly true of the dual snare drum parts in Patterns 2, 6 and 7 which should be assigned radically different voices if an effective contrast is to be achieved (follow the guidelines laid out in October's On the Beat).

As you'll see, I have stuck to 4/4 time sigs throughout, and none of this month's patterns involve triplets, so programming really couldn't be more straightforward. Just remember that achieving the right mix between instruments (something which cannot be notated on the grids) is of comparable importance to choosing the right voices - particularly when programming the more complex Patterns such as 1, 4 and 7. Remember, too, the importance of pitch in creating a degree of separation between voices - particularly the cymbal/bell combinations and the bongos/congas. Generally speaking, it's better to sacrifice the selection of the optimum pitch for an instrument when played on its own, than risk it being muddied by other instruments when played in concert.