EFFECTIVE DRUM PROGRAMMING
PART 2: The debate's been going on for as long as drum machines have been around: can they really sound human? NICHOLAS ROWLAND takes jazz drumming as his test case and tries to find out...
In this month's nail-biting instalment of The Rhythm Method, we're going to investigate various techniques for making programmed patterns sound more 'human', as well as looking at some short cuts to generating rhythm tracks with an apparently improvised feel. While the focus of our attention will be jazz patterns, the subtext is all about injecting the milk of human kindness into beat boxes in general. So even if you think that jazz is something musicians only do when they get too old to play music that people actually want to listen to, stay tuned.
On the face of it, jazz drum programming appears
to be a contradiction in terms. Jazz music is supposed to be all about the
spontaneous expression of heart and soul, while drum machines and sequencers are
soulless machines, the very opposites of spontaneity, creativity and having a
good laugh down the boozer after the gig. That was certainly true 10 years ago,
when drum machines simply didn't have the technical facilities to compete with
humans on a jazz tip. First, the sounds themselves were often not realistic
enough to be appropriate for jazz (though, to be fair, this was more an attitude
of mind than a valid technical issue). Second, and more importantly, early drum
machines just didn't offer
the necessary
control over dynamics and quantisation which are necessary if you want to
emulate the subtle nuances of a live drummer in full flow.
"...thanks to
cut and paste, you can quickly generate drum tracks which have an
apparently improvised feel."
These days, there are no excuses. Armed with the most basic GM module/workstation and the humblest of computer sequencers, you can produce jazz patterns that not only sound convincing, but swing with the best of them. The only real limit to your creativity is your time. Sequencers and drum machines only put out what you put in. If you want to create a rhythm track based around the idea that each bar is different from the next, then you'll have to be prepared to program every single variation yourself. From my own experience, I know it can take many hours to recreate the kind of spontaneous-sounding jazz track that any drummer worth their salt could lay down in a single take. Be prepared.
TO ERR IS HUMAN
One question which is perhaps worth spending a few lines considering is what exactly differentiates a rhythm played by a human from one created by a machine. Setting aside the issue of sounds and ambience for the moment, can most people actually tell the difference between a recording featuring a real drummer and one driven by a beat box? It was probably easier to distinguish in the early days, when a combination of lazy programming and a lack of onboard memory meant that drum machines gave themselves away by undue repetition. The lack of control over dynamics also meant that drum machines really did sound like metronomes -- not so much because of the regularity of timing, but because of the total consistency of the sounds. What makes music 'human', on the other hand, is the minor inconsistencies in the playing, in terms of timing, dynamics and the variations inherent in acoustic instruments. There's also this ephemeral notion of 'interpretation' -- which can, perhaps, be defined as an ability to creatively bend the rules to enhance the emotional pleasure of the music. Or to put it another way, if it ain't got that swing, it don't mean a thing.
DYNAMIC DUELS
As I mentioned last month, dynamics (the relative MIDI velocity levels of the different instruments) are crucial to creating a sense of movement within any style of drum pattern. Creating convincing jazz patterns requires even more attention to detail in this matter. Obviously, the easiest way to achieve a human feel is simply to program your rhythms in real time, using a velocity-sensitive MIDI keyboard, drum pads or drum machine buttons. I'd recommend this as your standard approach with cymbal parts, which often provide the fluidity of movement within a rhythm. (In jazz, it's the ride cymbal which is the dominant time-keeping instrument, as opposed to the hi-hats). Most sequencers offer a mixture of pattern-based and linear recording, so it's easy enough to build up a basic track from a series of step-time created patterns, then go back and record a new 'live' cymbal line over the entire track. Try also setting the quantise function to a very fine resolution, or turning it off altogether. You can normally go back and correct any really wayward beats after the event, using the over-quantise function.
TIME, GENTLEMEN, TIME
What originally really used to get up people's noses about drum machines was the fact that they kept 'inhumanly' strict tempo -- a charge which is still levelled at sequenced music per se. There are two issues here. One is about variations in tempo across the whole track -- in other words, the fact that people naturally speed up and slow down during different bits of a song. There's no reason why sequenced music shouldn't also speed up and slow down, and thanks to the wonder of sequencer tempo maps it's very easy to build this kind of variation into a song. In fact, whatever the style of music, one trick is to nudge the tempo up by a couple of beats when you hit the chorus or playout, and take it down a few notches in the bridge from the introduction to the first verse, or the bridge from the middle eight to the next verse, and so on.
The second issue concerns the minuscule variations in timing that occur within a pattern. Here we're touching on a human foible known in drumming circles as playing behind or in front of the beat. The fact is that the majority of human drummers (and, for that matter, most other musicians) rarely hit the notes right on the button. Some will have a natural inclination to play slightly early, others will play slightly late; some can go back and forth as the music demands. Playing behind the beat will drag the song back and make the track sound slightly slower than it actually is. You notice this in a lot of slow blues and funk numbers, where often the whole band hits everything slightly late. Playing ahead of the beat gives the song real urgency, making it sound faster even though the tempo hasn't actually changed. Again, this is easily replicated on most sequencers (and some drum machines), which allow you to shift patterns or entire drum tracks by a specified number of MIDI ticks. It's worth experimenting with this function, particularly on the snare when you've got a regular beat on the two and the four. But don't overdo it, or your drummer will just sound out of time.
Some sequencers and drum machines take this a stage further, with intelligent quantise functions which alter the MIDI velocity of certain beats, while also shifting the timing of certain beats by tiny amounts. But whereas early applications of this function imposed the changes randomly, it's now based on more careful analysis of the rhythmic pulse of particular styles of music. Personally, I think these functions work best when they're applied sparingly -- for example, to a fill or particular drum phrase rather than across the entire track. (See the examples box for further discussion of this.) Otherwise the drumming just sounds wrong rather than 'human'.
TIMBRE LAND
As most people are aware, an acoustic drum doesn't just get louder when it's struck harder, it also changes timbre, rising in pitch and exhibiting more pitch-bend. Cymbals will also change timbre according to where they are struck on their surface, and also how rapidly they are played. Some drum machines and sound modules simulate this through multi-sampled voices which will change according to MIDI velocity. If a sampler is the source of your drum voices, you can also easily set up velocity-sensitive cross-fades between different pitches of the same sound or, indeed, different sounds.
A similar effect can be achieved with more humble equipment. For example, the standard GM kit offers a choice of two ride cymbals, plus a more 'clangy'-sounding ride 'bell'. As a matter of course, I would use at least two of these sounds within a jazz ride pattern, if not all three. It really does make a difference. Similarly, when programming two bass drum notes in quick succession, try using a softer, more rounded one for the first beat and a sharper, heavier sound for the second.
RANDOMISATION
So far, so good. But while technology may be on our side in terms of making individual patterns sound more human, I appreciate that not everyone has the time and patience to laboriously trawl through a drum track beat by beat, instrument by instrument, tinkering about with individual velocities, timing values and so on. However, thanks to the power of cut and paste, you can quickly generate drum tracks which have an apparently improvised feel.
The process starts with the creation of a 1- or
2-bar 'master' pattern. With a jazz track it might be the archetypal jazz cymbal
rhythm, underpinned by a basic bass and snare figure. This is then copied to
several pattern locations -- an easy enough job whether you're using a
stand-alone drum machine or a computer-based seque
ncer. You then call up one of
these copies and start deleting, adding or moving a couple of cymbal beats here,
a couple of snares or basses there. Maybe just delete every fifth cymbal note --
whatever. The trick is not to think too hard about what you're doing, and for
this reason I often work in step time, because then it's hard to second-guess
the end result. What you should end up with is a family of 1-bar patterns, all
based around the master rhythm, yet each one slightly different. When chaining
these together to form the song, simply assemble them in a random order. Hence
the first verse might consist of patterns 1/2/3/4, but the second would be
2/4/2/3, and so on. Again, don't try to second-guess the result. When played end
to end, the finished rhythm track might sound a bit iffy, but once you've got
the rest of the instruments in place the result should sound more
coherent.
With a sequencer, applying this technique is even easier. For example, in the edit page of a program like Cubase you can easily sub-divide your master and variation patterns into smaller sections -- half-bars, or even quarter-bars, for instance, and then use these smaller building blocks to build up the complete drum track.
Once the other parts are in place, it's worth going back to the drum edit page and tweaking the patterns to better fit the structure of the track. For example, there might be places where the insertion of a crash cymbal would provide an accent or mark the division of a bar.
Et voila! What you now have is a rhythm
track with a large element of unpredictability about it -- almost as good as a
having a machine with its own mind!
The archetypal jazz
hi-hat/cymbal rhythm (you'll know it when you hear it, honest) is
based on a quaver/dotted quaver/semi-quaver combination. However,
this is played with a triplet feel, so in programming terms it's
easiest to program in triplets. So the patterns this month were all
created using a quantise value of 8th-note triplets (that is, 12
steps to the bar.) You'll see that a few examples actually use
16th-note triplets, but for the sake of making the grids easy to
understand, I've kept the grids quantised at 12 steps to the
bar. Last month we had
three dynamic levels, but this month I've used four. And instead of
giving them absolute MIDI velocity values, I've suggested a range of
dynamic levels to play with. Ideally, you would tweak each
beat/instrument, so that no consecutive values are the same.
Finally, while this month's examples are all based on jazz patterns,
the general points covered in the main body of the text are equally
applicable to any style of music where a human feel is
required. JAZZ PATTERN
A -- This is
the archetypal (some might say cliché) jazz rhythm, played using the
ride cymbal. Note, though, that even with a simple pattern such as
this, we're using the ride and ride bell sounds to add a little
extra interest to the rhythm. JAZZ PATTERN
B -- With more
blobs on the grid you can see that this is a more intricate version
of pattern A. Again we're mixing the ride bell and ride cymbals to
give more interest at the top end. I've also doubled up the
tambourine with the pedal hi-hat to add emphasis to the second and
fourth beats in each bar. JAZZ PATTERN
C -- The snare
fill towards the end of the second bar uses a mix of two snare
sounds to simulate the changing timbre of an acoustic drum. The
'double diamond' (brush snare, fourth beat, second bar) is a flam,
when two notes are played close together. JAZZ PATTERN
D -- This
example mixes sounds again -- bringing in the metallic sounds of a
timbale over the top of the brush snare during a short roll. The
psychedelic wedges are supposed to indicate the fact that one gets
louder and the other gets quieter -- but I guess you'd probably
worked that out for yourself. Timbale sounds are often quite
strident, so you might have to play around with the relative volumes
of the snare and timbale to get the most pleasing effect. GROOVE-QUANTISED
FILL -- This is
a simple jazz fill pattern which has been part-doctored using a
Cubase groove quantise, although only the bit contained in
the white box. The results are shown more clearly in the enlarged
section. The result is a lazy, lumpy snare fill which sounds very
human indeed! I would probably apply this quantise to any other
instruments which were playing at this time, so that the whole
'band' sounds locked in together, even though they're all 'out of
time'. Rather than applying these quantise treatments wholesale
across a song, I tend to use different treatments in different parts
of the song. There are times when you want things to sound tight and
absolutely locked into the groove, other times when you want to
'push' a chorus, or 'pull back' a verse. This may sound corny, but
think of the different character of each part of a song, then look
at how you might enhance them through playing about with the
micro-timing of beats. You can also try a
reverse approach. A lot of people will quantise the rhythm track to
death while being happy to input the rest of the instruments in real
time. What you can consider is copying instrumental tracks to the
drum tracks, then using the note-ons of the melodic parts as the
basis for quantising the drums. GHOSTED
NOTES -- If you
watch a jazz drummer playing, you'll notice a lot of tapping away at
the snare drum in between the main beats or accents. These are often
known as ghost notes and, while you often can't hear them when a
band is in full flight, they add a characteristic background wash to
a recording or live performance. The purists out there might
consider even taking all the attack off the ghosted sound and then
feeding it through a short reverb back into the main drum mix. This
also goes some way towards simulating the way that the snare will
vibrate whenever other drums in an acoustic kit are
struck. JAZZ IMPRO 1, 2
& 3 --
You've probably already got the idea from the main body of the text,
but here's a couple of patterns which have been chopped up and
reassembled. The toms in Jazz
Impro 1, especially in Section 1, give the pattern a strong theme,
so when putting the track together I've used this as the first bar
in each four-bar section.
Your starter for
10 is a cluster of four jazz patterns based around the archetypal
jazz cymbal pattern. In rhythmic terms there's nothing to blow your
socks off. What I'm more interested in here is illustrating some of
the techniques explained in the main article. Before we get into
that, though, some basic house rules: whereas rock and pop rhythms
are based on even-length notes, jazz rhythms are divided into uneven
sections based on combinations of quavers, dotted quavers and
semi-quavers.
Europe's No1 Hi-Tech Music Recording
Magazine
Sound On
Sound
Media House, Trafalgar Way, Bar Hill, Cambridge CB3 8SQ,
UK.
Telephone: +44 (0)1954 789888 Fax: +44 (0)1954
789895
mailto:info@sospubs.co.uk
Website:
www.sospubs.co.uk
© 1999 Sound On Sound Limited.
The contents of this article are subject to worldwide copyright
protection and reproduction in whole or part, whether mechanical or
electronic, is expressly forbidden without the prior written consent
of the Publishers. Great care has been taken to ensure accuracy in
the preparation of this article but neither Sound On Sound Limited
nor the Editor can be held responsible for its contents. The views
expressed are those of the contributors and not necessarily those of
the Publishers or Editor.