Speed/Pitch Correction for beginners

[StormySky]

Hi everyone-

I've been going through my hdd and have found many shows that are in need of a speed/pitch correction, but I have no clue where to start. I've gone through the other threads where people ask the same questions but I really haven't been able to glean anything from it. I know I should be using a program such as Reaper for the work, but I'm not quite sure where to go from there.

I had read in some threads how some people were able to "calculate" how off key a transfer is or how fast or slow it is, but how do you go about that?

Any help would be greatly appreciated!

[Swirling Panpot]

Hi everyone-

I've been going through my hdd and have found many shows that are in need of a speed/pitch correction, but I have no clue where to start. I've gone through the other threads where people ask the same questions but I really haven't been able to glean anything from it. I know I should be using a program such as Reaper for the work, but I'm not quite sure where to go from there.

I had read in some threads how some people were able to "calculate" how off key a transfer is or how fast or slow it is, but how do you go about that?

Any help would be greatly appreciated!

I can tell you how I operate.

Firstly I would comment that when available it is best to correct speed in the analog domain. If transferring vinyl, use the pitch control of the turntable, if doing cassettes, find a deck with a pitch control option, and set the pitch before starting the transfer.

You may note from many threads that the pitch is not always off by a fixed amount. It may vary over the length of the tape, or even during a song.

What is the correct pitch?

Our ideal here is to have the music sound as it did when it was performed. The good news for this band is twofold: having a keyboard in the band, (when they tuned) they were always correctly tuned to concert pitch. This is A440, or 440 hertz for the musical note "A". All other pitches are referenced from this one. Maybe one or two guitar strings would go out, but for Dave these could be tuned on the fly, or certainly between songs. Rick would tune Roger's bass when necessary, from the keyboard. That is one plus. The second is that they did not vary from the pitch at which the composition was performed. Careful With That Axe is in D. They did not do it in other keys.

How do you get the correct pitch?

Because I am a guitar player, I will correctly tune my guitar, and play along with the music. It does not take long at all to know if the tape is wrong compared to the live guitar. If you know where the pitch is supposed to be (by knowing the chords or key of the song being played), you can adjust the playback to match. Some people tune to the timbre of a known voice. This is more like "earballing" it, and I should imagine it to be inexact at best. But for someone like Jimi Hendrix, who tuned by ear and played songs in different keys, and seemed to favor relative tuning to concert pitch, such a method may be the best available.

One way to set your pitch is to find a section of the tape where the band is tuning. Go to the end of the tuning section (when they are in tune and ready to play the next song), and match that to a correctly tuned guitar or keyboard. If the guitars are out of tune, always tune to the keyboard. It should always be correct.

How do I match them?

It is easier in analog because a rotary dial or slider allows you to vary the pitch quickly on the playback device. If you are matching a digital source, I find this to be a process of trial and error. Somewhere in your software of choice there will be a pitch adjust effect. The great thing about digital is you can demo the effect many times before making your commitment. So for instance, get it set on the first song, then try the same value of adjustment on the last song and see if it still works. Another cool thing about digital is the so-called pitch bend, so if the pitch changes over the course of the song (in a linear fashion) you can set a preset to correct the whole song in one shot. Use trial and error (and undo everything each time you test) until you are sure you have what you want. Then adjust and save.

In Adobe Audition software there is a cool tool that shows you where a clear pitch falls on the scale. You can then watch the position change as you adjust. I can elaborate on this if necessary.

The real short answer is that pitch correction really is more of an art and less of a science.

I hope this helps.

[StormySky]

I can tell you how I operate.

Firstly I would comment that when available it is best to correct speed in the analog domain. If transferring vinyl, use the pitch control of the turntable, if doing cassettes, find a deck with a pitch control option, and set the pitch before starting the transfer.

You may note from many threads that the pitch is not always off by a fixed amount. It may vary over the length of the tape, or even during a song.

What is the correct pitch?

Our ideal here is to have the music sound as it did when it was performed. The good news for this band is twofold: having a keyboard in the band, (when they tuned) they were always correctly tuned to concert pitch. This is A440, or 440 hertz for the musical note "A". All other pitches are referenced from this one. Maybe one or two guitar strings would go out, but for Dave these could be tuned on the fly, or certainly between songs. Rick would tune Roger's bass when necessary, from the keyboard. That is one plus. The second is that they did not vary from the pitch at which the composition was performed. Careful With That Axe is in D. They did not do it in other keys.

How do you get the correct pitch?

Because I am a guitar player, I will correctly tune my guitar, and play along with the music. It does not take long at all to know if the tape is wrong compared to the live guitar. If you know where the pitch is supposed to be (by knowing the chords or key of the song being played), you can adjust the playback to match. Some people tune to the timbre of a known voice. This is more like "earballing" it, and I should imagine it to be inexact at best. But for someone like Jimi Hendrix, who tuned by ear and played songs in different keys, and seemed to favor relative tuning to concert pitch, such a method may be the best available.

One way to set your pitch is to find a section of the tape where the band is tuning. Go to the end of the tuning section (when they are in tune and ready to play the next song), and match that to a correctly tuned guitar or keyboard. If the guitars are out of tune, always tune to the keyboard. It should always be correct.

How do I match them?

It is easier in analog because a rotary dial or slider allows you to vary the pitch quickly on the playback device. If you are matching a digital source, I find this to be a process of trial and error. Somewhere in your software of choice there will be a pitch adjust effect. The great thing about digital is you can demo the effect many times before making your commitment. So for instance, get it set on the first song, then try the same value of adjustment on the last song and see if it still works. Another cool thing about digital is the so-called pitch bend, so if the pitch changes over the course of the song (in a linear fashion) you can set a preset to correct the whole song in one shot. Use trial and error (and undo everything each time you test) until you are sure you have what you want. Then adjust and save.

In Adobe Audition software there is a cool tool that shows you where a clear pitch falls on the scale. You can then watch the position change as you adjust. I can elaborate on this if necessary.

The real short answer is that pitch correction really is more of an art and less of a science.

I hope this helps.

Thanks so much for your response. I've only been playing guitar for about a year and a half, so my skills are nowhere near close enough to tune it by ear.

Hypothetically, if one wanted to pitch correct a tape from a specific tour (let's just say the In The Flesh Tour), could you compare the off-pitch/fast transfer to a correct pitch/speed of another concert from around the same time? (For example, trying to correct one of the MSG shows from that July with another one a couple days later)

[pm1532]

In Adobe Audition software there is a cool tool that shows you where a clear pitch falls on the scale. You can then watch the position change as you adjust. I can elaborate on this if necessary.

Please elaborate on that. I'm particularly interested in that.

[pm1532]

That's honestly really cool, thanks for the explanation.

[snagu]

[...]Since the pitch of this segment is so uniform, it only shows one pitch on the scale to the right: G6. At this resolution of photo it may look like C6, but on the Mac it is definitely G6. I am not a music theorist, so I am actually not positive of what the "6" refers to, but I do not think it is the 6th note of a G6 chord.

That's right: the 6 has nothing to do with chords. It's the octave. So a G6 is the note G one octave above G5. And there's different ways of counting the octaves as far as I'm aware, so I can't tell which octave this is exactly. But it doesn't matter in this case because all you are doing here is calculating a relative pitch adjustment.

[Friend of Squirrels]

Good stuff

[pelino]

Interesting stuff

I use a similar but different method

it is explained here

https://mega.nz/file/mBllmDIA#teX_3G...VzOzY_zR3ckq0M

hope it helps

Actually I refined it even more, but it will takes some time to update this explanatory pdf...

[Swirling Panpot]

Interesting stuff

I use a similar but different method

it is explained here

https://mega.nz/file/mBllmDIA#teX_3G...VzOzY_zR3ckq0M

hope it helps

Actually I refined it even more, but it will takes some time to update this explanatory pdf...

Nice job. I look forward to your updates!

[Swirling Panpot]

In Adobe Audition software there is a cool tool that shows you where a clear pitch falls on the scale. You can then watch the position change as you adjust. I can elaborate on this if necessary.

The first thing I need to say is as I think this through it seems impossible to pitch correct unless you know something about musical pitch in general, or absent that, that you have an exceptional ear for pitch. Otherwise I recommend leaving this task to those who are more attuned.

My example here will be for a uniform adjustment across a file, be it a song or a whole show. I am not even sure if this tool is available for a pitch bend.

The first thing I do is select a short segment of the file. Copy that segment, then paste it into a new file. This does two things: it insures that your testing is not accidentally destructive to the main file, and it gives you quicker processing times when you are testing. Once you have settled on a correction, you can apply it to the original file. I would always keep a copy of the original file, in case things go south!

New file = "Pitch test." This one is from the start of Shine On You Crazy Diamond. The performance pitch is a stable G minor. In the lower right you can see it is 10 seconds long.

Screen Shot 2020-09-28 at 12.18.58 PM.png

Next, select the whole file, then use the menu Effects > Time and Pitch > Manual Pitch Correction:

Screen Shot 2020-09-28 at 12.19.45 PM.png

Some of you might notice the option of Automatic Pitch Correction. You might think "dang, I'll just use that." Let me assure you it is good for a giggle and nothing else. I had the same thought, and it just made a big mess of the music. Maybe someone else knows something I do not, but it seemed to be hopeless as a usable tool to me.

A new window opens:

Screen Shot 2020-09-28 at 12.21.30 PM.png

Now, below the regular file waveform you can see a window of smeary color. This is the pitch display area. Since the pitch of this segment is so uniform, it only shows one pitch on the scale to the right: G6. At this resolution of photo it may look like C6, but on the Mac it is definitely G6. I am not a music theorist, so I am actually not positive of what the "6" refers to, but I do not think it is the 6th note of a G6 chord. Let's put that aside, as I do not think it is important. When using this example to do the correction, I was able to shift the pitch, but it did not display the shift the way I was used to. I put this down to "not enough variety of notes." So I sampled a different section, four seconds long, of David singing "Shine On You Crazy Diamond." I deleted the old audio, pasted in the new, and then I initiated the Manual Pitch Correction function, and this is what I got:

Screen Shot 2020-09-28 at 12.24.44 PM.png

Now on the lower right side you can see a wide range of pitches, and the squiggly colored lines to the left of that scale are actual pitches derived from the music.

Next, look up in the middle of the screen to the small window overlaid on the time scale. The words there are "db" and "cents." There are little rotary dials next to each word. If you hover the cursor over the orange db "+0" symbols and click and hold, you will get an arrow that points both left and right. You can drag this arrow right to increase the volume of the music, or left to decrease the volume. As you do this the little dial rotates clockwise or counterclockwise. Be aware that when you release from this action, the change will be made and the number of the change will NOT display. Therefore, if you are documenting your changes to the file, you must make a note of the change before releasing the mouse click.

The dial below the volume (db) is for pitch (cents). It operates the same way - drag right to increase pitch, left to decrease. Note the value of the adjustment before releasing. Use control+Z to undo the last action.

The difference with this pitch adjustment is displayed here:
Screen Shot 2020-09-28 at 12.25.10 PM.png

If you zoom in on this photo to the lower right you can now see two lines by the pitch scale. The blue line represents the pitch of that note before the correction, and its' location on the scale to the right is a reference to the musical pitch - in this case F. The green line above it represents the new pitch after the adjustment - the fact that it is above the blue line indicates graphically that the pitch adjustment went up, and that the pitch is now G. The scale mark between F & G is F#, so the adjustment shown is a whole step up, or two half steps (two graticules on the scale). Furthermore, the fact that the lines meet the graticules straight on indicates they are pitched correctly to that sound. If the green line appeared slightly lower, and between the two graticules on the scale, the sound would be said to be off pitch: flat of a pure G pitch, or sharp of F#.

Now some of you might make the astute observation that the lines themselves are not straight/flat lines. How is one to know which part of the line to match up with the scale on the right? Indeed, when a person sings, they often have inflection, or pitch variation which is not fixed to a given note. The same is often true with guitar notes. Gilmour loves to bend his notes. We are therefore looking for the flat lines, like the ones to the left and below the ones right by the scale. If you zoom in, you can see those lines sitting pretty much right on the grid marks of the scale. Flat lines are a better bet for matching absolute pitch. That said, remember that sometimes musicians play out of tune. Keyboard sounds are usually more reliable.

You can widen the view of the waveform or pick different test passages to find a good suitable sample notes for your testing.

So you make your adjustment on the test file, note the amount BEFORE releasing the mouse click, and then listen to the result. Use Ctl+z to undo, or you can type values into the +0 display (pitch down by typing -x where x is the amount of the adjustment), and you can then test and undo with very small increments until you are satisfied with the result.

You can then go back to the master file, copy a different segment, and test the same adjustment value. This may tell you if a bend is needed. I am no expert at pitch bending, so I will not be writing a tutorial on that.

Apply your adjustment value to the whole file and give it a listen. If you do play an instrument, make sure it is in tune and play along with the file. You can usually tell pretty quickly if your instrument and the recorded music are off pitch relative to each other. If so, go back and start over. Remember, you have saved your unadjusted file. I recommend against stacking one correction on top of another. Who knows what all that wonky math is doing to the music. Keep it simple. Also, doing all your corrections at a higher sample rate is better.

OK, those are my ideas. Any corrections or suggestions are welcome. Good luck!