Tuesday, May 5, 2009

Simulating Guitars with Synths

We synthesists are a strange lot. We have at our disposal the power to make incredible, never-heard-before sounds from scratch, and yet, sooner or later most of us end up using our synths to emulate existing instruments we might not know how to play in real life. And there's nothing wrong with that. In fact, learning to emulate other instruments can be a very enlightening experience if you take it seriously. Today, I'll help you tap your inner Jan Hammer and give you some tips on how to emulate rock guitar sounds.

1. Get An Amp Simulator

A very large part of how guitars in rock music sound is due to the amp and cabinets the guitars are fed through. Distortion effects are one thing, but the way an amp and cabinet effect the sound is actually a lot more complex than that. Fortunately, there are some great plug-in amp simulators on the market now (I use Native Instruments Guitar Rig), and since they are plug-ins, they spare you the headache of having to properly mic and record real, physical amps. (Although there is nothing wrong with doing that if you're up to the task!) As an added bonus, these types of plug-ins sound great on all sorts of sounds, not just guitar emulations.

2. Start With the Right Sound

While an amp simulator will get you most of the way towards emulating guitar timbres, you can't just feed it anything and expect good results. Experimentation will go a long way towards helping you figure out what works, but a little common sense will help you figure out what works. A raw guitar sound is a rather thin sound, so start with simple, one oscillator synth sounds instead of heavily detuned super saw leads. For chords, electric piano (particularly Wurlitzer type sounds) can actually sound pretty convincing. For leads, go for a monophonic lead like you might find on a Minimoog (which was Mr. Hammer's weapon of choice). Of course, you can also use a clean guitar sample provided it's well sampled, but simple synth sounds can work just as well if not better sometimes (for example, pitch bends sound better using a synth sound than a sample, in my opinion). So start with a simple sound. Let the amp and other effects add the organic qualities.

3. Voice Chords Like a Guitarist

The way chords are voiced on a guitar is quite a bit different from the way they are voiced on a keyboard. It's not a bad idea to pick up a beginning guitar instruction book that demonstrates the notes that make up different guitar chords. Of course, if you're just after the distorted rock sound, all you need to know is the power chord which is made up of the root note, one note a fifth up, and a third note an octave up from the root. This will give you big, full-sounding chords without the distortion muddying the tone which can happen with more complex chords. (Which isn't to say rock guitarists just use power chords, but power chords are certainly the easiest to emulate with good results).

4. Learn How a Guitarist Plays

Part of what makes instruments like the guitar so cool is that there is a wide range of playing techniques that can yield an amazing amount of expression. Not all of these are easy to emulate, but techniques such as trills, bends, and the like can be convincingly simulated with a little practice. Again, pay special attention to how these techniques sound. You can't just reach for the pitch bend wheel and expect it to transform your squarewave synth into a searing Eddie Van Halen lead. There are specific amounts of bend guitarists commonly use that are definitely not the same as what your pitch wheel defaults to. Just learning a couple of commonly-used expression techniques guitarists use can really increase the beliveability of your imitation.

There's obviously more to getting a realistic-sounding guitar emulation than just these 4 tips I've listed here, but when imitating real world instruments, it is often just a handful of subtle techniques that make the biggest difference. Do you have any favorite techniques you like to use for this sort of thing? Let us know!


dave romero (a.k.a visitour) said...

just to say, we guitarists have also "reciprocated" by trying to create quasi-synth sounds and fx. well, not me personally, but many guitarists have

adding to the pointers, start by limiting your pitch wheel to a major 2nd or a minor third to get a feel for string bends. They're not easy to emulate. a slow, wide-ish vibrato while bending would help

One guitar bend emulation that can be pretty convincing with a pitch wheel is where 2 notes a major 2nd apart are played simultaneously and the lower pitch is immediately bent up to the higher pitch. Guitarists do this on two strings.

I'd like to know how a synthesist would program this last.

Anonymous said...

I'm guessing Ronan Harris will be reading this article and getting all excited around about now ;)

Tom said...

Visitour - Although it would take a lot of practice to play correctly, you could probably emulate that technique by using aftertouch to modulate pitch. I seem to remember having an old pedal steel sample for my EPS that did that and you could bend single notes within a chord or interval.

Anu said...

Many modern synths have the ability to set the pitch bender to only bend either the held or not held notes for exactly the reason mentioned above.

Re: faking guitars:
1) You can BUY a guitar for less than the cost of many soft synths. Why not just get one and learn to play it, even badly? I guarantee it is more fun and sounds better than "faking" (I play guitar and synth, neither that well)

2) Go meet a guitar player and have them add to your track. More people = more fun = better music

Personally, I find "faked" synth guitars to be pretty cheesy and never convincing. Sampled loops are slightly better but really inflexible.