Assuming you want perfect, of course.
Part of what makes the nylon
string guitar such an interesting
instrument is that it has a rich vocabulary
of artifacts, from fret buzzes to
slides to fingernails scraping on the
lower strings’ metal windings. In fact
many samplers include samples of
these sounds, which can be brought
in by (typically) hitting a key harder
or using a controller, to help create a
more realistic emulation.
However, there can be times when
the artifacts are a distraction rather
than an enhancement. Before digital
audio editing came along, there wasn’t
much you could do about the situation,
but that’s changed: It’s now possible to
surgically remove, or at least reduce,
many of these types of artifacts.
I first used this technique when
working on a classical guitar album
by an artist who had some health
problems at the time. Most of his
playing was exceptional, but occasionally
some notes sounded “tentative.”
I found that in those cases,
there was some sort of sound preceding
the note itself, and deleting
that sound made the note ring
through with authority. Since then,
I’ve used this technique with other
guitarists to reduce or remove artifacts
that would spoil an otherwise
perfect part. If you take this to an
extreme, you can almost make a classical
guitar sound like it was played
by a robot with perfect technique—
but I don’t recommend this any more
than I recommend using Auto-Tune
or Beat Detective on everything!
Gather Your Tools
Doing this kind of editing requires a
spectral view of the waveform (Figure
1) so you can easily recognize the
difference between the artifacts and
the notes themselves, and perform
the digital audio equivalent of a
“window splice” in the frequency
spectrum. I use Adobe Audition 3 for
this, although Steinberg Wavelab also
gives an editable spectral view.
With Audition, call up the file and
go View > Spectral Frequency Display.
Adjust the resolution as
desired, then look closely at the
notes. Note attacks will have a
sharp, vertical line that extends from
low to high frequencies. Artifacts
almost invariably appear just before
the note attack. You can use any of
Audition’s selection tools to define
the artifacts as a selection; when
you do, a level control appears. You
can then use this to dial in the exact
amount of attenuation.
Surprisingly, it’s often possible to
remove the area completely and not
be able to hear that it was removed.
Sometimes, though, you’ll need to
reduce the gain (by a few dB) rather
than remove the section to retain a
realistic sound, or if you want to leave
a bit of the artifact sound but make it
less obvious.
Practice Makes Perfect
It takes a while to recognize what’s
an artifact and what isn’t, and to
determine the degree to which you
can reduce it. Life is often about
compromises, and this is no different;
you’ll find problems you can’t fix, and
conversely, you’ll be able to fix problems
you thought were unfixable.
In any event, if you’re willing to take
the time to do this kind of detailed
editing, you can produce the most
amazingly clean and clear nylon string
guitar parts you’ve ever heard