Assuming you want perfect, of course.
Part of what makes the nylonstring guitar such an interestinginstrument is that it has a rich vocabularyof artifacts, from fret buzzes toslides to fingernails scraping on thelower strings’ metal windings. In factmany samplers include samples ofthese sounds, which can be broughtin by (typically) hitting a key harderor using a controller, to help create amore realistic emulation.
However, there can be times whenthe artifacts are a distraction ratherthan an enhancement. Before digitalaudio editing came along, there wasn’tmuch you could do about the situation,but that’s changed: It’s now possible tosurgically remove, or at least reduce,many of these types of artifacts.
I first used this technique whenworking on a classical guitar albumby an artist who had some healthproblems at the time. Most of hisplaying was exceptional, but occasionallysome notes sounded “tentative.”I found that in those cases,there was some sort of sound precedingthe note itself, and deletingthat sound made the note ringthrough with authority. Since then,I’ve used this technique with otherguitarists to reduce or remove artifactsthat would spoil an otherwiseperfect part. If you take this to anextreme, you can almost make a classicalguitar sound like it was playedby a robot with perfect technique—but I don’t recommend this any morethan I recommend using Auto-Tuneor Beat Detective on everything!
Doing this kind of editing requires aspectral view of the waveform (Figure1) so you can easily recognize thedifference between the artifacts andthe notes themselves, and performthe digital audio equivalent of a“window splice” in the frequencyspectrum. I use Adobe Audition 3 forthis, although Steinberg Wavelab alsogives an editable spectral view.
With Audition, call up the file andgo View > Spectral Frequency Display.Adjust the resolution asdesired, then look closely at thenotes. Note attacks will have asharp, vertical line that extends fromlow to high frequencies. Artifactsalmost invariably appear just beforethe note attack. You can use any ofAudition’s selection tools to definethe artifacts as a selection; whenyou do, a level control appears. Youcan then use this to dial in the exactamount of attenuation.
Surprisingly, it’s often possible toremove the area completely and notbe able to hear that it was removed.Sometimes, though, you’ll need toreduce the gain (by a few dB) ratherthan remove the section to retain arealistic sound, or if you want to leavea bit of the artifact sound but make itless obvious.
It takes a while to recognize what’san artifact and what isn’t, and todetermine the degree to which youcan reduce it. Life is often aboutcompromises, and this is no different;you’ll find problems you can’t fix, andconversely, you’ll be able to fix problemsyou thought were unfixable.
In any event, if you’re willing to takethe time to do this kind of detailedediting, you can produce the mostamazingly ...