Killer Drum Grooves

By Julian Colbeck

Drums don't just fuel the groove, they define it. Put a hip-hop beat beneath a bunch of chords and you have hip-hop. Substitute a reggae beat and it becomes a reggae track. Swap that for a merengue and you're in Miami.

Anyone can make a drum kit emit drumlike noises. In MIDI it's even easier: just call up a drum patch with different drum and percussion instruments mapped out across the keyboard and go Doom, Flap, Doom-Doom Flap on notes C1 and D1.

So why do electronic musicians often find killer drum grooves so elusive? For the same reason that a ticking clock will either send you to sleep or fail to register after a while: an unchanging rhythm is boring. And once rhythm composers leave the cozy confines of a straightforward beat (for example, kick on beats 1 and 3, snare on beats 2 and 4, 16th notes on the hi-hats), they're often in uncharted waters.

Weaponry

It's not what you have; it's what you do with it. For example, Ringo Starr used essentially the same four Ludwig drums for almost the entire time he played with the Beatles. Nowadays, more sampled drum sounds are available on the market than an electronic musician can deal with in a lifetime. The heart of the matter is how you actually create your drum tracks from your drum sounds.

You have four choices if you stick with MIDI, five if you include audio samples. You can tap into drum sounds using a QWERTY keyboard, a MIDI keyboard, MIDI drum pads, MIDI files (drum grooves offered as MIDI performance data), or audio samples. Creating rhythms using a QWERTY keyboard is recommended only if you're completely broke or you're a computer nerd. Some form of MIDI keyboard, preferably one with at least a five-octave keyboard, is the way to go. It doesn't need to be expensive or have weighted keys. However, a keyboard that gives you the option of switching Velocity sensitivity on or off, or one that gives each keyboard zone its own MIDI channel, is preferable. This gives you the option of triggering individual sounds from one section of the keyboard while triggering a sampled loop from another. It also lets you combine modules so that you can, for example, use the kick drum of one sound module (using one MIDI channel) with the snare from another module (using another channel). We're talking options. We're talking crazy mixes, blends, and ideas. You want killer drum tracks? Crazy is good.

Whether you want to go quite as crazy as investing in a set of drum pads is another matter. If you were a drummer in another life, then a modest set of drum pads will be a lifesaver. It may even put you ahead of the field in terms of producing realistic drum grooves. For everyone else, drum pads are not magically going to turn the rhythmically challenged into Chester Thompson. Accept this and move on.

Getting started

Once you have a MIDI controller, a sound module or sound card, and a computer sequencer, where do you begin? Just hit Record and play something. More killer drum grooves are created by polishing up an improvised groove than by painstakingly programming each note. Never be afraid to let your fingers flail about from time to time, because there is no "wrong way" to construct a drum loop.

One approach is to record yourself playing for a minute or so, then listen to what you played, keeping an ear open for segments that show promise. Cut out the good segments, paste them into a fresh track, and use them as the basis for your groove. Another way to work is to set up a four-bar loop and build up a groove, instrument by instrument, using your sequencer's Overdub Record mode.

To quantize or not to quantize?

Quantization is the mapping of your rhythm into a particular set of timing values, such as 8th or 16th notes, with a sequencer. Quantization was initially designed to push and pull notes into strict time so that recordings would sound more professional. In some areas of hip-hop, R&B, and electronica, such templates still work well. In fact, if this is the result you're looking for, you might as well record with a heavy quantization factor already in place.

But if you want natural-sounding grooves (similar to what a live drummer would play), then you need to record freely, without quantization (see Fig. 1). Afterward, you can either judiciously apply subtle quantization or abandon quantization altogether. Most sequencers now offer a wide variety of quantization settings.

(see figure #1)
FIG. 1: The highlighted selections show unquantized kick drum notes that give a live feel to MIDI tracks.

Abandoning quantization doesn't mean you have to end up with lollopy, out-of-time drum grooves. It is relatively simple to look at your unquantized groove in either a grid or musical notation and physically adjust one or two hits that would benefit from editing. For example, if the internal structure of a groove works well except for a noticeably late first kick drum beat, don't quantize the whole groove; just move that first kick drum to the downbeat.

This kind of tweaking doesn't have to result in Swiss-watch accuracy. Moving the position of a kick drum downbeat from 000 to 002 or 003 often gives the groove a more natural give and take.

You don't need to quantize every instrument within a pattern, either. If you have your eye on the pulse and want to create a "speed garage" groove, for instance, set up a fairly standard four-to-the-floor kick, with the snare pattern on beats 2 and 4 and the hi-hats playing 16th notes. Then, quantize only the hi-hats to a shuffle pattern.

If you have a second sequencing system available, a cunning alternative to quantizing is to rerecord a groove using the other sequencer running at its own internal tempo. Begin with a groove that you like but that is out of time within its current sequence. Loop the groove and adjust the tempo on your sequencer until the groove plays perfectly in time. Rerecord the groove on your second system at this new tempo. This type of trickery is well worth doing if you have access to hours of drum pad-generated drumming.

Here are some additional groove therapies at your disposal.

Substitutions. Using the previous methods, almost anyone can churn out a kick/snare/hi-hat pattern of some merit. To take a pedestrian groove to the next level, try some simple instrument substitutions. To spice up a chorus, a middle section, or the third verse of a song, a real drummer will often go to the ride cymbal. A basic groove can remain the same; just transpose the hi-hat parts to the ride cymbal. A more elegant substitution is transposing closed hi-hats to a ride-cymbal edge and open hi-hats to a ride-cymbal bell.

Tempo. We are living in a wonderful time as far as variations in tempo are concerned. Drum 'n' bass artists, like the Prodigy or Chemical Brothers, gleefully storm along at speeds of 140 and 150 beats per minute, while TLC and R Kelly like to shimmy about at a groovy snail's pace of 60 or 70 beats per minute.

Typically, a sequencer's default tempo is 120 beats per minute, and although it's very easy to leave it there while you're working, don't. Get in the habit of experimenting with tempos. You may get a killer groove by playing half-time in a fast tempo, or by playing a sequence back at double or half speed (not all sequencers have this ability, but it's a good one to look out for).

Jungle, drum 'n' bass, big beat it seems as if the names given to these predominantly Euro-inspired beats change almost monthly. Many are based on sped-up Latin or hip-hop beats. The artists working in this field often use synth-based drums. You can enhance the sped-up effect of a groove by inserting a wide-range pitch bend (up to an octave) in your snare track (or the entire drum track if you want to get really crazy sounds). Now record a second pass, physically moving the pitch wheel on your keyboard. This is both simple and highly effective.

Remember that the tempo does not have to be rigid. A chorus that comes up a metronome marking or two can increase the realism of a track. Don't feel you have to go back down to your original tempo thereafter. Try raising the tempo again on the next chorus. The application of consistent dynamic tempo changes is a skill in itself. Create a separate tempo track so that you can "conduct" the groove in this manner once it has been recorded. Make several passes at your tempo adjustments until you're happy with the song's ebb and flow.

Dynamics. Dynamics can add a human feel to the groove. If executed poorly, however, dynamic changes can be an annoyance. There are a couple of obvious candidates for variation in volume, each requiring its own types of subtlety.

The "ba-boom" type of kick drum beat will always sound more natural than two hits of equal Velocity. But if a consistent kick drum part on beats 1 and 3 varies from 105 to 127 (in MIDI values), your groove will probably sound insubstantial and amateurish.

Snare drum hits have a small range of ideal Velocities: full on for the main hit and less than quarter strength for the ghost notes (see Fig. 2). Programming the ghost snare beats is very difficult. If your drum loops require this type of subtlety, consider using MIDI or audio samples instead. Generally, these kinds of sampled grooves have the right feel in the ghost notes.

(see figure #2)
FIG. 2: Radical shifts in the Velocity of snare drum hits help you emulate the ghosting effects that real drummers achieve.

Hi-hats can give away that you're listening to a MIDI track. Programming the minute fluctuations in volume and tone that live players generate can be tricky. A straight 16th-note hi-hat pattern will sound mechanical when each note is played at equal strength and in perfect time. To minimize this effect, go into Edit mode and randomly make some of these notes louder or softer and earlier or later (see Fig. 3). If that doesn't work, substitute MIDI or audio samples.

(see figure #3)
FIG. 3: Adding variations in Velocity to the hi-hat parts increases the pattern's realism.

A good tip for tracking hi-hats is to record them apart from the rest of the groove using two or more keys on the keyboard. The sounds you initially hear may be different from what you want, but that's okay. You can always edit them to trigger hi-hat sounds later. Using two or three fingers almost always yields groovier-sounding patterns than stabbing at the same note with one finger.

Exploring the position of each instrument in a pattern is another option. Because drummers often play hi-hat parts slightly ahead of the beat, consider nudging the entire hi-hat track forward within the pattern. This will add realism, along with some urgency, to your rock beats.

The element of surprise. Individual cymbal hits (as opposed to patterns) are used for punctuation, most commonly on the downbeat of the first bar of a new section. Remember that a crash cymbal played without a kick drum beneath won't sound real. Splash cymbals and China cymbals are commonly played at the same time as the snare.

Crash cymbals don't have to be on the downbeat, of course. One of Mick Fleetwood's most beguiling traits is the way he puts the crash cymbal on the second beat of the bar. In a song with a steady groove, it's a simple but powerful technique that makes the listener wake up and reevaluate what's happening.

Audio versus MIDI. This debate could fuel an entire article. The reality is that both MIDI and audio have their place, and both have limiting and liberating factors. Here are a couple of points to ponder.

The good thing about MIDI is its flexibility: MIDI allows you to edit a groove's rhythm, tempo, and instrumentation quickly. In addition, MIDI takes up very little computer processing time and memory compared with audio. However, it's difficult to generate a realistic groove or feel using MIDI.

Audio gives you instant gratification. You like what you hear? That's how it'll always sound. In addition, audio tracks have ambience, which is something you have to create with a MIDI performance. On the other hand, audio doesn't allow you to separate the instrumental parts the way MIDI does. And making changes to tempo and pitch takes up processing power. Finally, audio files are memory hogs; an audio sample takes up ten times the space that a slice of MIDI data does.

Audio Samples

Sampled drum loops aren't hard to find just leaf through the pages of EM and you'll see dozens of ads for these products. The large number of commercially released drum loops should give you a clue as to their short life span, stylistically speaking. With some notable exceptions, sampled loops fall into the category of "use and lose."

But it doesn't have to be this way. Customize, combine, and be creative with audio samples. This not only increases their efficacy but also allows you to use and abuse the same samples many times over without sounding redundant. There are programs that let you customize loops in terms of tempo and pitch more efficiently than by simply playing samples within your sequencer.

You can't take effects out of a sample, but you can certainly add them, such as reverb, delay, and drastic equalization curves. Delays are particularly appropriate for drum grooves because they themselves can generate rhythm. You probably wouldn't want to slap a multitap delay over the loop of an entire drum kit. But delay on a single snare hit, mixed in with a loop, can be a real groove infuser. The same trick works with other percussion instruments such as claves, triangle, and tambourine. Using plug-ins in a digital-audio sequencer environment gives you the greatest amount of control over delays.

Lo-fi is particularly hip at the moment, and there are a number of plug-ins on the market that let you age a sample in the appropriate manner. To do it the old-fashioned way, tweak the filter-cutoff parameter on your sampler. Another trick is to run the sample through a stompbox, such as a distortion pedal or envelope filter. Even if you have the effect bypassed, you will probably notice an interesting change in the sound.

MIDI files

Instead of being captured with microphones, a live drummer's parts can be played using an alternative MIDI controller such as drum pads or a MIDI trigger, captured in a sequencer, and served up as a Standard MIDI File (SMF). The advantage of using SMFs is that you can twist and tweak a groove almost limitlessly, while still retaining the human qualities a real player generates.

You must choose your own sounds with a MIDI file, of course, and the results will depend on the equipment you have. Even modest drum sounds from a midpriced sound card or GM module take on new life when being "played" by real drummers.

Adding delays to a MIDI file is also possible. You can, for instance, extract the snare from a groove, place it onto a separate track, universally reduce the volume by at least 25 percent, and then experiment with delay factors within your sequencer (sequencers will always offer a range of "in-time" delay factors, but sometimes it's the ones in the cracks that inject the coolest grooves).

Groove combo

Very few recording artists would dare to use a sampled loop as is. And with good reason. A drum groove, however killer, has to fit in with the rest of a song. Therefore, it's important to view each groove in context.

The flexibility offered by mixing and matching audio with audio, MIDI with MIDI, audio with MIDI can prove crucial if you want the ability to deconstruct a groove later. If your entire drum track is based on a single audio sample, your options are limited. But if your groove is built on an audio sample, some MIDI grooves, and extra percussion on top, then each part can be continually tweaked, muted, processed, or soloed at different times throughout the song.

Let your ears and the song determine what works and what doesn't. Mix a straight beat with a swing or shuffle beat. Or mix a beat that's completely out of context (perhaps in a compound time signature like 11/8) with a straight 4/4 sample. This gives you a couple of choices: let the two run, and see if you like the polyrhythmic aspect of it (the grooves in this example will hit the same downbeat every 11 bars of 4/4), or truncate the 11/8 pattern so that it loops after four beats.

One of the broad appeals of rap and hip-hop is the way artists in this genre create intricate polyrhythms by layering two or more drum loops. You can get the same effect by layering two MIDI drum loops, using different kits on different MIDI channels. On General MIDI instruments, the drums default to MIDI Channel 10. Some GM modules impose no restrictions on using other MIDI channels for drums. Some units do, however notably Roland GS and Yamaha XG modules. Fig. 4 contains an example of the code that allows you to coax GS and XG units into freeing up MIDI Channel 9 or 11 for drums.

(see figure #4)
FIG. 4: Here's an example of the code used to circumvent the GM drum default.

Dial G for Groove

Infectious drum grooves fan the flames of creativity. But just plugging in an off-the-shelf loop from a sample CD will not get you there. Whether you're using MIDI libraries, a sequencer, or your own fingers on a keyboard, putting a little extra thought and effort into your rhythm tracks is the secret behind a killer groove.

Use every resource you can cutting, pasting, looping, processing, and so on to build up or break down a groove. The better the fundamentals are in your track, the less soul-searching you'll need to do later.

Julian Colbeck has traded life on the road as a keyboardist for a more dignified midlife occupation running the U.S. branch of Keyfax Software/Hardware.

This article presented courtesy of Electronic Musician magazine.