Hey guys!
Eric Tarr here for theproaudiofiles.com.
In this video, I'm going to show you four basic methods of creating pitch shifting effects
inside of a digital audio workstation.
A basic idea or concept of a pitch shifting effect is to give you as the audio engineer
the ability and control the frequency of a recorded signal.
Increase the frequency or decrease the frequency.
It's up to you then to decide how you want to use this as a creative effect.
There are several different methods to do this.
I'm going to show you a very primitive method first that kind of replicates how pitch shifting
effects were replicated on an analog tape machine.
Recording on an analog tape machine, an engineer would have to choose how fast the tape was
going to go through the machine.
What you could do after you recorded is play back the tape at the wrong tape speed.
If you played it back at a faster tape speed or a slower tape speed, it would change the
pitch.
The first thing I'm going to show you is how you can do a similar sort of thing in a digital
audio workstation.
This is going to recreate some of those famous vocal sounds like Alvin and the Chipmunks,
where you'd pitch shift it up, play it back at a faster speed, and then change the tone
and timbre of someone's voice.
Or you could play it back at a slower speed, and it would kind of give you a much lower
voice.
There are also some much more musical examples using this kind of effect on a tape machine,
where The Beatles recorded the piano solo on In My Life at the wrong tape speed intentionally
so they could play it back to fit with the key of their song.
Just several examples of doing this sort of effect.
How you can replicate this in a digital audio workstation is just change the speed or the
length of this signal that you've recorded.
I'm going to be working with this vocal recording here that goes along with this acoustic pop
song.
Let me play the song and then get to the different methods.
[mix playback]
First thing I'm going to do is show you how to use time compression and time expansion
to change the length of this file.
Essentially playing it back at the wrong speed.
I'm going to accomplish this by using something called Elastic Audio.
It's an ability for your digital audio workstation — Pro Tools — to change the length of
a file — to compress it in time, or expand it over time.
I'm going to do this here by turning on a specific one called Varispeed.
This is going to replicate the idea of a tape machine.
Playing it back at a different speed.
Now that I've got it turned on and analyzed, what I'm going to do — I've got this clip
highlighted — come up here to the top, find clip, and find the elastic properties menu.
Here, I have the ability to go in and do time compression and time expansion.
So I can make it twice as long by typing in 200%.
You can see that now, the signal has been stretched out.
Let's listen to how it sounds.
[vocals stretched]
So the result is I pitch shifted it down by 12 semitones,
or one octave.
In order to undo this, go the opposite direction.
Here, I'll go up a time compression and expansion factor of 50%.
Now it's going to be half as long.
Let's listen to the pitch now.
[vocals shrunk]
So I've gone up — pitch shifting up 12 semitones, or one octave.
Now, this sort of effect, it accomplishes the pitch shifting.
The issue that comes up though is I've also changed how that signal lines up with the
rest of my song.
So if I were to go in and have it be half the length, let's listen to the vocal in the
context of the song.
[mix with fast, high vocals]
So what I've done is thrown off how the signal synchronizes with the rest of my track, and
that's a problem.
This is a very primitive method of doing pitch shifting, so it might not work in all situations,
especially if you're trying to make sure your signal lines up with your song.
So I'm going to show you a second method then that's going to preserve the timing information
of the signal.
This is going to be a similar thing, except I'll use an Audio Suite processor.
Up here, I've got the clip highlighted.
I'm going to go into pitch shift and turn on Pitch II.
This is an Audio Suite processor that analyzes and processes the entire signal at one time.
So if I wanted to go down by an octave, I could go from middle C down to an octave below.
Change it by 12 semitones and render that whole file.
You'll see that the timing is actually preserved.
[mix with deep vocals]
Or I could go in the opposite direction.
I could go up an octave.
[mix with high vocals]
If I like, there's a parameter on here called the mix knob, or mix slider that will allow
me to blend in some of the original unprocessed, or the correct pitch, to go along with the
octave.
So now, if I were to render this, you'll hear both the correct, original signal and also
the one that's been pitch shifted.
[vocals with normal and high]
So this works pretty well with vocals.
It's also a pretty interesting thing to consider with things like bass or electric guitar.
This is the Audio Suite processor that processes the entire signal at one time.
This isn't the only way to do it though.
There's also a version of a plug-in that runs in real time that I'll turn on over here under
the pitch shift.
It's also called Pitch II.
The interface looks very similar.
The only difference is now when I play back the signal, now I can make changes on the
fly.
It doesn't have to render the entire signal at once.
[vocals, adjusting pitch on the fly]
So that's another method of creating the pitch shifting effect by using the real time plug-in.
Now, the limitation of this processor is the fact that all of the notes are getting changed
by the same amount.
All of the notes are getting changed up an octave, down an octave, or by some other note
in the musical scale.
What I'm going to do is show you another processor that then can be used to give you more fine
grain control to pitch shift individual notes.
So here, I'm going to change Pitch II over to another kind of processor.
This one is called Melodyne.
There are also similar processors or plug-ins, not just Melodyne, that perform this similar
kind of way of analyzing the signal.
So here, what you have to do is transfer the signal in first so that the plug-in can analyze
it.
I'm going to turn this one on and play
it back.
[mix]
Now that I've played the signal in, what I can do is pick individual notes and change
their frequency.
So if I want this note here up...
[pitch going up]
[mix with adjusted vocals]
I can make these things go up instead.
[adjusting vocal pitch]
[mix with adjusted vocals]
So now you don't have to process the entire signal by the same amount.
You can make individual choices about what you want the notes to be.
So there's four basic methods creating pitch shifting effects.
Everything from very primitive methods to more sophisticated methods, including this
one here called Melodyne.
That's all I've got for you today, so until next time, take care guys.