No Strings Attached, p.2

The basic timbre of the unprocessed electric guitar, like most plucked stringed instruments, has a respectable amount of the fundamental, with virtually every harmonic represented. There are so many different guitar sounds, though, that it's tough to generalize. For an in-depth examination of the topic and a selection of sample synth patches for guitar emulation, read A Synthesist's Guide to Acoustic Instruments, by Massey, Noyes, and Shklair.

A few tips:
’ΔΆ Use a very fast attack time to get a solid picking sound. Map the synth's attack time to decrease as key velocity increases so that you get more pick sound (faster attack) when you hit the key with greater velocity. You can accomplish a similar effect if you're using a sampler and can modulate the sample start-time from velocity. When you want to get an extra-hard picking effect, you can layer a small amount of "pluck" patch-a separate program with very fast attack, almost no sustain, and very fast release-and trigger it with velocity, using a high velocity threshold (low sensitivity).

’ΔΆ Program the synth or loop the sample so that the sound has a longer sustain time than a real guitar string but doesn't sustain as long as you hold down the key. (Guitarists rely on signal processing for extra sustain; keyboard players can ''have their cake'' with sample looping and synth-envelope programming and still use signal processing.) Use a fast release time so you don't smear the notes in fast passages or when emulating hammer-ons and pull-offs, but make sure the release isn't so immediate that you get an audible "pop" at the end of the sound.

’ΔΆ Try layering two patches or samples, one of which is the basic guitar sound and the other a feedback sound that has a delayed, long, slow attack. The feedback only enters if you hold the key long enough, then continues to swell as you hold the key. If you use your ear and program the feedback sound to attack as the main guitar sound decays, you can achieve an effect reminiscent of Jimi Hendrix's feedback at the beginning of "Foxy Lady."

’ΔΆ One of the difficulties of guitar emulation is that the strings interact, causing sympathetic resonating harmonics. It's possible to program a poor person's version of this by such tricks as bringing in a delayed sine wave at the third (or other) harmonic. You can produce much more elaborate and accurate extensions of this idea if you want to dedicate a lot of programming time and multitimbral voices to the task.

’ΔΆ By programming a separate patch with a very fast attack, short sustain, moderately fast release, and simple waveform, you can emulate picked harmonics. Use your ear to tweak the envelopes. You can use velocity cross-switching, pedal-triggered switching, etc., to shift between the regular guitar patch and the harmonics patch. If you can play fast, accurate leaps, you can map the harmonics patch to a separate zone higher up on the keyboard. On an Ensoniq EPS sampler, you can layer the different samples and bring them in with the Patch Select buttons, the left pedal in the

double footswitch, or MIDI controller 70. The same holds true of bringing in a "chicken-pickin''' patch (a variation on the "pluck" patch) or sample.

’ΔΆ A l2-string guitar uses six pairs of strings, with the lowest four pairs tuned in octaves. You can emulate the tuned pairs by using two instruments or two oscillators tuned in octaves, with an extremely short delay between them to account for the time it takes to pick both strings in a pair. The low note sounds first on downstrokes. This also can be accomplished with a sequencer by transposing duplicate notes up an octave and very slightly time-shifting the transposed notes.

Signal Processing
Any effects processors guitarists use are available to keyboardists. Chorusing, flanging, delay, distortion, and reverb are fair game. But synths and samplers output line-level signals far hotter than passive guitar pickups, so if you process your signal with a guitar effects box that expects to see a direct signal from a guitar, remember to pad down the synth's output level considerably.

Electronic instruments also have a dynamic range far wider than that of an electric guitar. Before you add effects, it's a good idea to compress the dynamic range to about 6 to 12 dB, as experimentation dictates. It's best to do this within the patch, but you also can use an outboard compressor. Guitarists often use compressors ahead of their distortion devices, but this is mostly to increase sustain by keeping the signal from decaying too fast, which isn't as crucial with a properly programmed synth-patch sample.

Before routing the signal to an effects device, roll off the extreme highs, using your synth's filter or a parametric equalizer. Otherwise, the extraordinary high harmonics generated by a synth will aggravate clipping when put through a distortion device. The distortion box should give you all the highs you need.

A large part of the classic electric-guitar sound is the amp and speaker combination. Sometimes there's nothing like the real McCoy. Try using an old tube amp with separate channel and master volume pots and a pair of 12-inch speakers. By sending the processed signal to this rig, overdriving the channel circuit, and miking the speakers with a Shure SM58 or similar mic, you can get that classic tube amp sound. Alternatively, you can use a classic amp with a Marshall SE100 speaker emulator (reviewed in the November 1991 issue of EM), or a Tech 21 Sans Amp (reviewed in August 1991). The Sans Amp does a little emulation of its own to produce classic amp tones without an amplifier and is plugged directly into the mixer.

Get Together
It's a blast to watch a guitarist's jaw drop when a synthesist comes impressively close to The Sound. Using a synth or sampler to emulate a guitarist also somewhat reduces the need for the genuine article. And with ten fingers and strong chops, you call go beyond mere emulation and pull off licks and chords no guitarist can play. But I still prefer having a hot guitarist around. The biggest thrill conies from challenging each other and combining forces to really rock the house.

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