Minor differences between two recorded guitars

Question

According to my previous question Panning distorted guitars (get the attack sound) to get the desired effect you need to record two identical guitar parts (talking about guitar part of course because it's impossible to record identical byte code). So I did. But there are minor differences like this:

You can see that it's kinda whacky in terms of timing, but timing can be fixed using flex time/nudge/anything else. If you look at the third chord of the riff, you can see that they have slightly different duration (top track is left channel and bottom is right). Is it criminally problematic while doing post production or you can hide these differences by applying distortion (I'll use it anyways though), reverb, stereo delay (to match the differences between channels)?

Answer 1

It's hard to tell from the images what it actually sounds like, as there's no time-scale, but that's the criterion I'd use - what it sounds like.

Sometimes, a good groove is based on the average beat-centre provided only by the whole band, it doesn't rely on any single part. Listen to some early Stevie Wonder for a perfect example of this - try Superstition.

If you can very clearly hear the timing difference; if it sounds 'poor', then by all means shift & stretch one until it doesn't. Small time-stretches will not be heard anyway, assuming your DAW has a decent algorithm to do it.

A good way to do this type of edit is cut early, before the next transient [always cut at zero-crossings anyway, but cutting early helps this too].
You can then slide your transient into place, time-stretch then apply a short cross-fade to the part before it.
Cutting early means you don't hit the transient with your cross-fade, it's done in the tail of the preceding note, so you'll never hear it.

What you don't want to do is end up actually quantising both takes so hard that all aspects of feel disappear & you have a perfect but completely sterile guitar part.

There's a lot to be said for interplay between almost identical parts spread left & right. If you sterilise them completely, the 'magic' will disappear.

Some DAWs can do this automatically, stretch & quantise [or iteratively quantise] to a grid. You can try this but be prepared to Undo, as it's not always the 'magic fix' they promise.