Practicing what you learn by listening is the key to realistically synthesizing acoustic instruments. If you're a keyboardist, you're expected to be an arranger and an orchestrator who can work in a wide variety of styles. In the course of a day's work, you're often obliged to substitute for other players. So how good are your impersonation skills? Unless you're well prepared, you might become uncomfortable when a project requires an arrangement that includes acoustic instruments and it falls on you to become all the instrumentalists. Such undertakings can be daunting, even torturous, unless you're sure that you're up to the task. Whether you're doing high-profile project work, live gigs, or recording in a basement studio, successfully emulating acoustic instruments is all about the sounds and the presentation.
How convincing are your emulations? Instruments that play ROM- and RAM-based samples (including computer-based streaming-sample players) provide the flavor of the real thing, but depending on what you do with them, they can stop short of sounding realistic. The sounds are only half of the equation; your performance skills are the other half. I'm not talking about keyboard dexterity here, but rather your ability to translate your understanding of acoustic instruments into keyboard performances that sound like the real thing. You must learn to fool most of the people, most of the time.
The programming capabilities of your synthesizer or sample-based instruments will vary. The more flexible the architecture, the more programming depth — and hence, the greater nuance — you can achieve. An elegant emulation is the product of the quality of your samples, your understanding of the acoustic instruments you're emulating, your performance skills and creativity, and the power of the architecture that allows you to shape your sound. For the purposes of this article, acoustic instruments are defined as instruments that require no electricity to play. It's okay to stretch that notion to include some electric instruments such as electric guitar, bass guitar, and the entire family of instruments derived from their acoustic predecessors, such as electric violin, cello, or sitar.
LIBRARY SCIENCE Begin by developing a systematic knowledge of your tools. It should be obvious that you must learn how to program your synths and samplers well enough to understand their capabilities and limitations. It's equally important, however, that you organize your sounds thoroughly enough to have lightning-fast access to them. Creating and maintaining a customized set of acoustic solo and ensemble instruments is an absolute requirement. By investing the time it takes to lay the foundation, you'll have a valuable resource to build upon. Constructing a well-defined library of instrumental sounds will reduce the overall patch-tweaking process for all your subsequent sessions. In the long run, adequate preparation will save you time and money. Even if you have a pricey ROM-based workstation, the latest sampler, an extensive soundware library, and advanced sound-modeling software and you spend tons of time tweaking sounds, nothing substitutes for talent. The performance talent must still come from the musician who uses those tools. Part of applying that talent is learning to effectively shape sounds in real time, just as musicians have been doing for hundreds of years.
Well-designed electronic musical instruments offer sound-shaping capabilities that allow you not only to duplicate the performance gestures of acoustic instruments but also to bring out your individual personality by expressing your own musical voice. Some of the most important tools for musical expression are real-time controllers such as pitch benders, mod wheels, ribbon controllers, breath controllers, continuous-control pedals, and footswitches. Once you learn to use them, you can apply MIDI-controller techniques to most programmable sample players, samplers, and synthesizers, whether they're based on hardware or software.
SAMPLE ABUSE
Have you ever been in a music store's keyboard department and seen a customer dial up an acoustic-guitar program, depress the sustain pedal, play a few left-handed chords and right-handed blues licks, and remark, “Yuck! That's a guitar? That's awful.” And have you seen a customer try to romance a lyrical solo out of a stock sax patch, only to quack away like a wounded duck or a bad harmonica? Is it really the sample's fault? Players are much too quick to blame the instrument or the samples.
The plain truth is that even a great sample that's played poorly usually sounds bad. Conversely, a poor sample played well sounds acceptable (though not necessarily good) to many listeners. You've probably scrolled through a synthesizer's stock solo-acoustic-instrument patches and been uninspired. Finding an electronic instrument that can easily take the place of real acoustic players is difficult, but not impossible.
FOCUS ON THE BASICS
Obviously the quality of the samples matters, but the performance matters even more. What techniques will generate the most realism? A significant portion of the illusion comes from first doing the brain work and then mimicking musical gestures repeatedly — in a word, practicing. A solid understanding of how real instruments perform is necessary before you can apply any synthesis concepts or techniques effectively. Some useful considerations can help you as you approach creating and performing elegant, convincing emulations.
To understand what's necessary to successfully emulate an acoustic instrument, bear in mind this useful sequence of steps: absorb, analyze, re-create, and practice. Absorption is all about listening and learning from what you hear. Analysis is the intellectual process of identifying the components that make an acoustic performance come to life. Re-creation brings those components to life using electronic instruments. And practice, to paraphrase the old adage, is what makes your emulations perfect.
An important step is learning to listen analytically, even surgically, with an ear bent toward reconstructing a particular instrument you hear; that's especially true with ensemble music. To emulate an instrument, you need to learn and practice its characteristic nuances. Then, the real magic comes from tweaking the raw materials at hand to suit your needs in a particular situation to reconstruct those nuances and subtleties.
It's impossible to overemphasize that listening to the real thing is a prerequisite for emulating it. Listening is an ongoing process for any electronic musician who wants to progress and evolve better programming and performance skills.
Consider any acoustic instrument from three different perspectives: how the sound is produced (whether it's blown, bowed, plucked, or struck), its changes in timbre and loudness, and the kinds of modulation a player employs. Compare the acoustic player's techniques to a synthesist's techniques. When a solo flutist performs a musical passage, for example, notice the constant variations in tone color (timbre), vibrato (modulation), and dynamics (amplitude). Pay attention to how the player controls the instrument's loudness and timbre while breathing life and emotion into a performance. Contrast that vision with the straight playback of a static sample, and you'll see a vast difference.
To get a clearer picture, consider the flute's performance characteristics. When a flute is blown easily and softly, it produces a warm tone with a subtle attack transient; conversely, when it's blown sharply and forcefully, it yields a brighter, thinner tone with a sharper, more noticeable transient. Apply those observations to your programming, and as you listen to the real instrument, think about all the variables of its sound. Does it have a wide dynamic range? What happens to the transients as they change from almost nonexistent to the sharpest, shrillest extreme? Try to visualize an acoustic instrument from a simplified perspective, and then work to the more complex as time (and your equipment) permits.
That kind of analytical thinking must be practiced as well. Applying such thinking when you program synth and sampler patches will really pay off. Programs should be designed to respond to musical performance gestures; controllers should be programmed to allow a reasonable range of hands-on control across a wide range of musical passages and styles. Practicing controller movements in tandem with note performances is the key to achieving a greater degree of realism.
IDENTIFY THE COMPONENTS
Music moves in real time and in dynamic space. Musical performance, and especially improvisation, has extensive physical requirements. If a musical phrase contains 32nd notes played staccato at a dynamic of ppp immediately followed by some legato half notes with the dynamics gradually building to ff and ending on a final sfz, you should be thinking, “How can my synth patches allow me to produce that much variation on the fly?”
The key is advance preparation; you need to methodically organize various articulations — legato, staccato, marcato, and so on — into separate programs that you can access quickly. Better still, build a minimum set of versatile, pliable programs that allow you to perform a range of expressions. Without adequate preparation, the number of program changes and the speed that such changes might require in live performance would present daunting challenges.
To successfully analyze musical performance, it's important that you draw parallels between a real instrument's capabilities and your synth's programmable parameters and real-time-controller capabilities. Then, dig a bit deeper. What do the transients sound like as they respond to your playing across a wide dynamic range? What does the body (which equals the tone minus the transients) of a sustained tone sound like when played ppp and increasing to fff? How does the acoustic sound change when a note is released, either with an immediate stop or by fading out? Does the instrument's body resonate a few milliseconds after the performer stops playing? How would you express the sound you hear in terms of waveforms, filters, envelopes, and modulation settings? How would you best control the sound given your selection of physical controllers? In other words, how will you synthesize the sound?
Consider that a jazz tenor-saxophonist performing bebop has a different musical vocabulary than a classical (yes, I did say classical) sax player or someone performing 1950s doo-wop tunes. Sax players scoop up to certain notes, the final note's pitch might drop off at the end of a phrase, or the player can nail a note's pitch dead on. You also have all those “false” fingered notes with their peculiar timbres to contend with.
To accurately emulate any instrumental performance, you should study the instrument, the style, and the players that inspire you, as well as any particular aspects you want to capture. You need to carefully analyze the player's tone, phrasing, and nuances of articulation such as vibrato and dynamics. The player's approach can change depending on his or her musical style, knowledge of theory, emotional state (mood), and performance level (experience). Variations in tone can come from other factors, too, such as differences in instrument construction and design.
RE-CREATE TO EMULATE
Most keyboards ship with a collection of programs that include acoustic-instrument programs, but they often don't sound very convincing out of the box. A little tweaking can dramatically improve their playability and realism. Customize the programs by assigning additional controllers to appropriate parameters for hands-on real-time control. Seize any opportunity to shape timbre, amplitude, and modulation characteristics in real time.
Using keyboard Velocity with an assortment of controllers, you can control the dynamic range of the filter and amplitude simultaneously and in varying amounts. The end result is a program that responds more like an acoustic instrument. Well-crafted programs allow for plenty of variation to provide musical depth and to fuel a player's spontaneous creativity. Don't underestimate the playing skills you need to master in order to deliver a realistic emulation from a synthesized model. A player should understand the real instrument as thoroughly as possible; good keyboard chops just aren't enough.
Ultimately, deciding which controllers to use and what parameters they should control will determine how realistically you can shape your sounds. Your goal is to find the easiest and most natural way to play and manipulate sounds in real time. Performance gestures that require awkward movements will be a hindrance to coordination and interrupt the flow. Try to use the most likely physical controller whenever possible. For example, you'll probably want to use a breath controller when you're emulating a wind or brass instrument and a ribbon controller when you're emulating a fretless stringed instrument or adding vibrato to a violin.
Adding spice to an evolving emulation can increase its realism, but what kind of spice? For a flute, it might be adding an overblown harmonic that's introduced at the highest Velocity levels, or adding a bit more chiff when you move the modulation wheel forward. Perhaps you can enhance realism by adding a bit of wind noise modulated by amplitude and filter envelopes that respond to Velocity. The key is to experiment and discover what works.
PRACTICE AND POLISH
Once a particular technique is learned, it must be practiced. To perfect your results, it is essential that you practice performance gestures, controller moves, and patch-change timings. Be careful that you don't overuse your real-time controllers, however, or you risk producing sonic caricatures. Work to refine your movements; that refinement is what often makes the greatest difference in the end result. Practicing your controller moves will go a long way toward improving realism. The extra work is always worth the effort.
The degree of realism you achieve is directly related to several factors, including how much you listen to music in the style you're trying to emulate and how much you practice the musical gestures that define that style. Equally important is the quality of the samples and the variety of articulations you have at your disposal. Other issues are the limitations of your synth or sampler and your skill as a synth programmer.
Working with a variety of sampled articulations is generally better than having a single articulation. With good programming, you might be able to squeeze enough variation from a single articulation, but the more sampled articulations you have at the beginning, the better your end result will be. Doing the extra programming work ahead of time will pay off in the long run. Successfully programming controllable crossfades and cross-switches is a special challenge. Good results largely depend on the flexibility of the synth or sampler and how well the samples are sonically matched across articulations and dynamics. Imagine being able to play a single program and articulate a wide range of phrasings from legato ppp to a legato crescendo and a presto staccato ff passage in real time and doing it convincingly. Well-crafted programs can increase your freedom in performance.
MODULATION CONTROLLERS
What follows are a few controller tricks that can help you program your emulations for greater realism. Although synthesizers and samplers don't all offer the same controllers or level of programmability, you can adapt these techniques to whatever programmable controls your instrument has to offer.
You can apply many of these concepts and settings to a variety of emulations in the same instrument family, such as double reeds, flute and piccolo, trumpet and cornet, and solo strings. For illustration purposes, I'll try to suggest a few emulative articulations.
Many instruments within a family will require a similar set of controllers. For example, certain controllers and modulation routings are most useful for emulating a wind instrument. Breath control works quite well for controlling amplitude, highpass-filter cutoff, and the attack, decay, and release times of the amplitude and filter envelopes. In reasonable amounts, keyboard Velocity works best for controlling amplitude-envelope parameters. If your synth has a ribbon controller, use it to control pitch for manual vibrato. To simulate the timbral changes that accompany vibrato, route the ribbon to modulate filter cutoff.
Personalize your vibrato. It always amazes me how many people can instantly identify a particular artist by his or her tone and vibrato. Many guitar, string, and horn players strive to develop signature vibratos, just as vocalists do. Instead of using a mod wheel or Aftertouch to control vibrato depth, try using your pitch bender or ribbon controller to create your own signature vibrato. By rocking the pitch wheel up and down (or joystick left and right) or wiggling your finger on the ribbon, you can control depth and rate with a single controller in one smooth motion. That technique has a threefold benefit: it promotes spontaneity and individual style, it produces a more realistic result, and it allows seamless integration of pitch bend and vibrato (see Fig. 1). Fig. 1: In this example, Pitch Bend is applied to a sustained saxophone note that breaks into vibrato.
Tremolo control. Similar techniques work just as well on tremolo. Consider a flute's modulation aspects, for instance. Flute players can play sustained tones without modulation until they want to add tremolo. Then, they increase the depth and character of tremolo in real time. Most synths allow you to patch a controller to adjust tremolo depth and speed. The mod wheel, breath controller, and control pedals are all good choices for varying LFO depth and rate. Such an approach yields far more realism than programming an envelope generator with predetermined delay, attack, and decay times. For even better results and to take the technique a step further, try controlling amplitude with a spring-loaded pitch wheel or joystick (with Pitch Bend disabled) to create an even more natural tremolo (see Fig. 2).
If you can patch the pitch wheel to control both amplitude and pitch, you can produce an effect in which you control a very slight amount of Pitch Bend and a wide amount of amplitude change from a single source. And if your synth lets you change your pitch wheel from bipolar to unipolar, you can get identical results when you push up or pull down the pitch wheel.
USE YOUR RIBBON
Point your browser at the EM Web site (www.emusician.com) and listen to my trumpet emulation, which takes full advantage of the ribbon controller patched to Pitch Bend and amplitude (see Fig. 3). That technique works quite well for simulating horn slurs and natural vibrato, and it's great for horn shakes. Velocity controls the amplitude envelope to deliver better control of dynamic shaping, and hence, more realism. (Kurzweil's V.A.S.T. engine offers FUNs that let you quantize the output of controllers such as the ribbon, which works great for horn falls or guitar-fret finger slides.)
Consider the ideal flute emulation; the amplitude and timbre can change dramatically. A real flutist controls modulation by means of flutter-tonguing and changing tremolo from narrow and fast to slow and deep. How can a synthesist gain more of that sort of control and range in real time? If you learn to use your controllers effectively, you can deliver good performances by controlling dynamics, timbre, and modulation.
One technique is to use keyboard Velocity to modulate the amplitude envelope. If your synthesizer or sampler lets you patch keyboard Velocity to the amplitude envelope's attack time, adjust it so that a soft key strike produces a slow attack (say, 2 seconds) and a hard key strike causes an immediate spike (the minimum attack setting). Adjust the amplitude scaling to taste; a wise range is less than 50 dB. Use the same technique to adjust releases, too; the slower you release a key, the longer the release time, and the quicker you release a key, the shorter the release time. Consider the emulated instrument's timbre as it changes across its full dynamic range and adjust accordingly.
Another useful technique is to route keyboard Velocity to control the filter's cutoff and envelope modulation. If your synth has a highpass filter, patch the lower Velocities to lower filter cutoff (to add more warmth) and the higher Velocities to raise filter cutoff (to thin out the tone by removing some of the fundamental). A resonant highpass filter can work miracles with the right modulation.
By the way, a synth that offers a mono ynch mode can help players with fat fingers to avoid those occasional, accidental ghost notes. Nothing blows a solo woodwind emulation faster than two tones sounding simultaneously.
PRACTICE BREATH CONTROL
Using a breath controller in combination with a well-programmed patch can produce amazing results. Patching breath to simultaneously control amplitude envelope, filter envelope, amplitude crossfading or cross-switching points, and vibrato depth and rate provides tons of control from a single source (see Fig. 6). After all, real brass and woodwind players control their instruments by means of breath control. So work on your cyclic breathing, and whatever you do, don't hyperventilate!
Certain considerations become obvious as you investigate emulating a particular instrument. For example, a six-string acoustic guitar can only play six notes at a time, and the lowest note you can normally play is E2. A solo woodwind instrument can play only one note at a time with no overlap; consequently, you should program the envelope so that it doesn't retrigger with each new note. Avoid playing any accidental grace notes, too, or you might spoil the illusion. Obviously, I've just scratched the surface here. Your studies can extend more deeply as your time and gear allow. I hope that these ideas start you thinking about what you can do to go beyond factory patches. The more you know about the original instruments, their note ranges, and their performance limitations, the more realistically you'll be able to emulate them.
GOING ELECTRIC
Let's examine everyone's favorite: the electric lead guitar. When you consider the electric guitar's dynamic, timbral, performance, and modulation characteristics and capabilities, you realize that emulation is a staggering undertaking.
To illustrate, I'll explain how to emulate a distorted rock guitar with wah-wah. Begin by layering a few sampled articulations such as picked notes, mutes, harmonics, and other goodies you might have available. (If you're using a sampler, you might be able to throw in a few chunks, chords, and dives, as well.) If you can assign Velocity or the mod wheel to crossfade from mutes to picked notes, the transition will be much smoother. To cross-switch between the samples using Velocity, I suggest assigning soft Velocity values (say, 1 through 60) for mutes, medium (61 through 118) for sustained notes, and full on (119 through 127) for harmonics. One of my favorite tricks is to layer different feedback samples. I layer two heavily distorted sine waves — one tuned 19 semitones higher than the fundamental pitch and another tuned 24 semitones higher. By using Aftertouch to crossfade between the two harmonics, you can control the balance between the sustained guitar tone and the harmonics, making it possible to fade from the fundamental to a harmonic and then up to the next harmonic.
Next, add distortion and effects to taste. To provide a wah-wah effect, assign a control pedal or the mod wheel to control a resonant lowpass filter. Use the pitch wheel for vibrato and the ribbon for trills, bends, and whammy-bar dives. Some synths provide independent note bending, so you can bend one note up as other notes sustain, unaffected by Pitch Bend messages. That ability can help you emulate stringed instruments such as fiddles, pedal steel guitar, and Dobro, and even ethnic instruments such as koto.
Chris
Martirano was director of product development for Kurzweil Music
Systems for over 12 years. He has worked with synthesizers since
the early 1970s and takes after his world-renowned uncle, Salvatore
Martirano.
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