Audacity, removing glitches from a sound track (the easy way)

 I found a collection of files in my archive I didn't know how to handle. I'm not into music editing so, no wonder. One thing I know is that sounds, shorter that 5ms, is not possible to hear.

This version of Ubuntu (20.04) displayed headphones as icons for some of the so I started Audacity to see if I could find out their heads and tails. They showed up as a whole CD by the "Klematics". Nice.

Checking what's in the files, you will get the idea why.

I noticed, when playing it that there were some glitches, when listening they sounded like a click. I thought I would try to get rid of them. I din't rally know how these glitches came about but  think i'ts reasonable to think they they just might be where the separate parts are... parted, but on the other hand.. well, I'll be content by finding them and fixing them.

I found that to zoom horizontally you could left click the fields to the left of the graphs. The middle say "0"  it says "0.5" etc. Left clicking got you a looking glass and right clicking expanded the graphs vertically up or down depending on where you clicked. This wasn't what I needed, I wanted to expand then horizontally. I found that Ctrl-1 and Ctrl-3 expanded respectively shrank them horizontally. Perfect!

Now I needed to find the glitches. First I used a high degree of expansion horizontally. To move the graphs sideways I needed to use the scroll-bar below. Grabbing the slider, the movement was too fast. Clicking in the "track" the slider was sliding in, made the slide go sideways one page at a time, but! using the high degree of expansion resulted in so short pieces of the graph moving in sight I would probably still be sitting there clicking, getting a carpal tunnel syndrome.

It was reasonable to lessen the resolution to make more of the graph pass by at each click. After a while I thought I'd got the hang of it. I was on my way to eliminate the glitches.

Glitches may certainly look in many different ways, my glitches looked like this:

Putting the cursor on the glitch and doing Ctrl-1 one or more times made it it looked like this:

Expanding it even further (Ctrl-1), I could mark the area with precision (the expanded view is not the same glitch! Sorry, you will get the idea anyway):

Pressing the "Del" key on the keyboard removes the part that is highlighted, which is a bout 1ms in length. I can guarantee, you will not be able to distinguish it, even if 1ms of real music should have been deleted.

But; this poses the interesting (for nerds like me) question: If I could predict what should have been in the place of the glitch? Could I then replace it with a new part making the music perfect. Yes you can. 

You can mark any part of the graph, press Ctrl-c and then move to another location and Ctrl-v this part in place you've marked. Using the Ctrl-1 you can expand the graph to the level where you can see each single sample of the sound level, count them, find a new part of your liking, in the material, of the exact same size and copy it to your place of preference. I could copy the marked part to the part between 45:52:8930 and 45:51:30 where something seems a bit undecided, Like this:

In this image each sample is designated by a dot. I could then cut out a part of the graph of the exactly right size (number of dots) and replace the part where there seems to be no action, just after 45:51:8920. We're in the milliseconds here :0).

What the result would be, it's up to you (and me) practicing. A string, swinging sinusoidal, would be possible to predict, in real life... well, it depends.

It was a most interesting exercise, making me interested in more fiddling.