Making MIDI Sequencing More Realistic, Part 2: Drum Parts

PART 2: In last month's issue, Paul Farrer offered hints and tips for making your programmed MIDI instruments seem more real. This month it's the turn of drums and percussion. This is the last article in a two‑part series.

When asked if he thought Ringo Starr was the best drummer in the world, legend has it that John Lennon, rather cuttingly, replied that he didn't think that Ringo Starr was even the best drummer in the Beatles. And thus started nearly four decades' worth of jibes and derision aimed directly at the one member of the band who essentially holds the whole ship together. We've all got our favourite 'drummer' jokes, yet secretly we are all aware of just how important drumming and percussion are to the modern‑day process of music making. A quick look at the current state of play in the sample CD market will reveal just how popular drumming and percussion sample CDs are. Why should this be? After all, most sound modules these days come stuffed with nearly as many drum and percussion sounds as you could ever hope to use, software programs are now so clever that they are capable of making musical decisions all on their own, and drum machines extol their 'human' or 'realistic' rhythmical features. Perhaps one source of our percussion paranoia is that we are all a little bit unsure of our own ability to construct interesting yet 'legitimate' drum patterns. How do we know that what we program into our sequencers could actually be played in real time, and should this even matter? If percussion paranoia is taking over your life, help is at hand. Relax, don your Spandex strides, your headband and your 'Metallica Live in Stockholm' T‑shirt, and let's get back to basics.

To Drum Or Not To Drum

As we saw last month, when you're programming any instrument part into a sequencer it's vitally important to continually bear in mind not only the kind of instrument you are trying to recreate, but also the playing style relevant to the piece you're working on. So it is with drums and percussion, the main difference being that, generally speaking, the rhythmic feel and tempo are the first things to be established when you're constructing nearly any kind of music. This is why so many programmers and producers start recording 'from the drums up'. It's easy to see why the drum loop has etched itself so deeply into the landscape of popular music production — the loop certainly takes a lot of the decision‑making and hard work out of having to start from scratch, and can very often define the whole feel and style of everything that is laid down on top of it.

Leaving drum loops aside for the moment, you can still approach a track with this 'drums first' attitude, but it's worth taking time to think about just what kind of drum and percussion instruments you'll be using. Turning to drum machines and sound modules can often cause 'optional paralysis' — by that, I mean having so many different sounds to choose from that it seems impossible to know which ones to use and, perhaps more importantly, which ones to leave out. The world of MIDI has, in effect, put you in a huge room surrounded by almost every drum and percussive instrument you could possibly need — and then you're expected to pick exactly the ones that will work best for your piece of music.

Listen to your all‑time favourite records and pay close attention not only to what the drummer and percussionist are playing, but also to how many different instruments they are actually working with. You may be surprised to find out that there isn't as much instrumental variation as you might have thought. Take Ringo's kit, for instance: bass drum, snare, hi‑hats, two cymbals and a couple of toms. The modern‑day 'stadium‑sized' drum kit, which takes a team of roadies six days to construct and into which the drummer has to be lowered from a crane, may look great on stage, but whether this 'bigger is better' approach actually makes for better records is an arguable point. Therefore, when trying to recreate the drum kit realistically via MIDI, the first thing you need to consider is what sounds to use.

The Kit

It seems sensible to start with the bass drum, and you can usually find at least three or four knocking around at the bottom end of the keyboard, each with varying degrees of thump or thud. This is the time to really think about what kind of a kit you want to work with. For example, is it a rock kit or a jazz kit? Should the drum samples have any built‑in ambience or will you be adding effects later? Of course, the attack, the tuning, the decay, and the general tone of the bass drum (and most of the other drums) will all add to the 'character' of the kit. I've found that bass drums tuned slightly lower are good for giving a track a more atmospheric and laid‑back feel (jazz drumming is notorious for big, flappy bass drums), whereas tighter or higher bass drum sounds work nicely for more precise drumming, where the 'tick' on the front end of a sample is accentuated.

The bass drum/snare relationship is one of the most crucial sonic decisions there is to make. Generally speaking, the snare acts not only as the other half of the 'boom‑tick' rhythm combo, but also plays an important role in defining the style of the piece. You don't need me to tell you that there are as many different snare sounds as there are US dollars in Bill Gates' bank account, but it's worth remembering that one real snare drum is itself capable of a thousand different tonal changes in the hands of a decent drummer.

Just as with the bass drum, when choosing a snare sound it's important to know just how flexible the sample is. Is it, for instance, velocity sensitive? Are there more than two or three different samples velocity cross‑faded, and if so how does it 'feel' when you play it via a keyboard or drum‑pad system? How much ambience is inherent in the sound and could you add more if you needed to? All of these questions are worth a brief look at before you decide which sounds to select.

To take hi‑hats as an example, General MIDI would have us believe that your average hi‑hat has exactly two states; open and closed (which is rather like saying a Ferrari is either going fast or not moving). The key to unlocking the expression of any drum sound is finding the degrees of variation between these two states, and your choice of drum sample should reflect this. Drum modules like the Alesis D4 have made life a little easier by including a number of different hi‑hat samples recorded at varying degrees of 'openness'. Clever programming of a sound such as this (for example, velocity crossfading more than one sample per key) is another sure‑fire way to make your hi‑hat work seem more realistic. With tom‑toms, think sensibly about the actual number of different drums in the kit you're trying to recreate. Also consider whether the tom samples in your sound module are actual recordings of differently pitched tom‑toms or simply one tom sample detuned by three semitones as you play further down the keyboard.

Programming Tips

The modern‑day drum kit hasn't changed a vast amount over the years. Even with the greatest set of pedals, advanced construction techniques and clever drum positioning, most Earthlings still only have a finite number of limbs with which to play. Or to put it another way, with two legs and two arms at their disposal at any given time, even the world's greatest drummers can only be quadraphonic. Bear this in mind when you're tempted to indulge in fancy playing (find me a real drummer who can play three cymbals at the same time over a tom fill!) and concentrate instead on the essential elements — bass drum, snare and hi‑hats.

In a standard 4/4 drum pattern, the bass drum (right foot) can be seen to play on beats 1 and 3, while the snare will play on beats 2 and 4. Over this the hi‑hats might work in 16ths or quavers, with the left foot controlling how open or closed the two cymbals of the hi‑hat are. Obviously, if the snare work gets any more complex and requires both hands (such as when playing a fill) the right hand playing the hi‑hat has to move over to the snare, leaving just the left foot to operate the hi‑hat pedal. Likewise, if the drummer uses the right hand to hit a cymbal or a tom, the hi‑hat work has to stop. There's a maximum of four different drums being triggered at any one time — and so it should be if you want to program a drum kit realistically via MIDI (see Figure 1).

It's About Timing

Quantising is called upon to atone for a multitude of timing sins, and its awesome powers would seem all the more crucial in the case of drumming: after all, the drums hold a track together, right? Well, yes and no. Of course solid timing is important to eliminate sloppiness, and if your rhythmic foundations aren't right it'll be almost impossible to add other instruments on top, but the drum track also has the power to drive and guide the song in other creative ways. Real drummers working without the benefit of click tracks generally speed up in choruses and pull back a little during verses. This is a perfectly natural and musical thing to want to do, and even the minutest change in tempo can be just the thing to really lift a certain section of a track.

Computers, as a rule, don't like things to be 'fuzzy', and are continually tempting us to be exact and consistent with timings (probably because it makes the maths a little easier). If you do tend to quantise much of your drumming, why not try increasing the tempo in a chorus or solo section, even if only by a BPM or so? While the change may not even be instantly perceptible, it could make the difference between a good track and one that sparkles with life.

Staying with quantisation for a moment, again think about the feel of the drum track you are working on. Is it acceptable, for instance, to play slightly behind or ahead of the beat to create a certain effect? And what about slight rallentandos (slowing down) over a tom fill, moving into a key change for a bit more drama before picking up the original tempo in the new key? (Instant Pink Floyd!)

If you do feel the need to quantise the bass drum as a firm foundation, you might want to try leaving your hi‑hat and snare tracks unquantised. Any dynamic differences (or volume expression) you can add will also help a great deal, and will add believability to a MIDI drum track — though it may take you a little longer to do. Chopping a drum pattern up into different sections to work on is another good trick. For instance, you could put together a fairly straightforward drum phase lasting seven bars, most elements of which could be quantised for greater accuracy, but in the eighth bar why not drop in a short, unquantised snare fill? This is a musical feature that the listener can pick up on and, if it's done well, could fool the ear into believing that the whole phrase is played by a real live human — who also just happens to have terrific timing. This trick works particularly well for percussion sounds.

As long as your foundation drum tracks are solid enough, you can be quite flexible with the timings of certain percussion parts, to give them a more human feel. Inserting the odd unexpected triplet or trill is just the sort of thing a live percussionist would do to add their own stamp to a performance, so you shouldn't always be tempted to lay down a percussion groove that you like and simply copy it to all parts of the song.

Just as with choosing drum kit sounds, deciding which percussion sounds to use can be tough. My only rule of thumb is that it's better to have two excellent and flexible percussion sounds that work well together and sound realistic (such as a good pair of conga multisamples) than a handful of mediocre percussive bits and bobs that happily 'busy up' a percussion track without really adding anything to the song.

Drumming Effects

There are a number of tricks a drummer can use to spice up a drum track, and it pays you, as a programmer, to be aware of them.

• FLAMMING GROOVY: One of the most popular is the 'flam'. When a note is flammed, it simply means that both sticks hit the drum but one arrives fractionally earlier than the other. Flams are particularly noticeable in rock tracks, where you'll often notice monster‑sized tom fills lasting a bar or more, but they can also be heard in the percussion section too, with hand‑flams on tablas and bongos.

The best way to programme flams is to record your tom track (or percussion part) as usual, then copy the sections you want to flam to a separate sequencer track and impose a negative delay of anything between ‑6 and ‑30ms. The resulting 'note doubling' effect is made even more realistic if you also reduce the velocity of the earlier notes slightly, so that the loudest note is on the beat, with a slightly quieter drum preceding it. This flamming effect also works well on snares and odd percussion noises, but be warned: the effect (like many others) should be used sparingly. Too much fancy drum work can have a detrimental effect on the rest of the track.

• ROLL WITIT: One of the hardest effects to recreate believably via MIDI has to be the snare roll. If you actually listen to a real snare as it crescendos over the course of a roll, it doesn't just get louder — the whole dynamic and character of the sound changes too. It's naive to think that you can replicate this entirely using samples, but you can certainly get close to the 'feel' of a snare roll if you follow a few simple guidelines. Firstly, never quantise a roll, no matter how long it is. The best thing to do is mark off the area that you'll be 'rolling' over and slow the track right down. Make it ridiculously slow if you have to (25BPM!) and record the entire roll flat, without any increase in note velocity or speed, from the position you want to start from to the end point (usually on a separate record track, for merging later). Playing the roll back at normal tempo will tell you if the speed feels right, and once you're happy with it, it's time to look at note velocity.

In Logic's Hyper Edit page, just as in the Cubase Key Editor, creating a crescendo is a simple enough procedure — just draw a new velocity curve onto the display bargraph. In older programs, such as Creator and Notator, this feature is in the Process Data page. Most other programs, however, have the ability to force crescendo and diminuendo parameters over certain marked areas. Of course there's going to be an element of trial and error when performing this function and, particularly with older programs, it tends to be a destructive process. As you might need a few attempts to get it right, be prepared to make a copy on another track, just in case. Simply tell the crescendo function to begin at a velocity of 001 at the start of your roll and end somewhere towards 120 and the computer should work out the rest. Also, if you have a way of controlling filters or EQ on your sound module or sampler, all the better. You might like to start with a fairly 'closed' or damped sound at the start of the drum roll, and brighten the top end as the roll progresses.