Translator: Tanya Cushman Reviewer: Peter van de Ven
Good morning.
I wanted to take you back
to that incredible Bobby McFerrin video that started us off today
and take a closer look at what might be happening there,
and I'm going to spare you my terrible singing, so don't worry.
So just to recap quickly,
Bobby started by giving the audience two notes:
this one,
and then by moving a little bit to his left, indicating a higher pitch,
this one, right?
Then they went back and forth between the two.
And when he jumped a little bit further to his left -
indicating a higher pitch -
but without singing it,
the entire audience landed on this one.
Right? It was amazing. You saw it.
And of course, this begs the question,
why this pitch?
Why not this one or this one or any number of higher pitches?
I suppose it's possible that everyone in the room that morning
had their musical education at the hands of Maria and the von Trapp family,
as in (Music: "Do-Re-Mi"),
but that doesn't seem like a totally satisfactory explanation.
So back to the video.
The audience is now in possession of three notes:
two that were given to them,
and this one that they had to come up with on their own.
Then Bobby jumps to his right and gives them this lower note,
and they have a total of four.
And from that point on, they're off to the races, right?
All he had to do was indicate
whether he wanted them to sing higher or lower.
But, slowly but surely, they added to their range
all of these notes down to here and back up.
And they did it together, without hesitation,
as if they'd just come out of rehearsal.
It was really incredible.
How do we explain that?
How do we explain Bobby's comment at the end of the video
where he said that this works wherever he tries it,
regardless of culture, regardless of geography.
The pentatonic scale, the five-note scale, which is what they were singing -
one, two, three, four, five - right?
just in two different registers, a lower one and a higher one.
"The pentatonic scale," he said, "just works."
Wouldn't it be nice if there was some sort of universal law of nature
that would help us explain
how someone in New York or in Beijing or in Dubai
would complete this musical puzzle and arrive at the same results?
Well, it turns out that there is such a thing,
a universal acoustic phenomenon that addresses this precise question.
It's called the "harmonic series," or the "overtone series,"
and it works a little bit like this.
So, tell me what you hear.
(Plays C)
You might think that all you're hearing
is this low and rich and resonant note that we call "C,"
which is produced
by its corresponding strings inside the piano, vibrating from end to end.
And you're right, but you're only partially right.
Because as the laws of physics remind us,
while that string is vibrating in its entirety,
it's also vibrating in two equal parts, down the middle,
and then three equal parts and four quarters and five fifths
and so on and so on.
And each one of those divisions produces higher and higher tones,
overtones.
And they occur in a very specific order.
And the wonderful thing
is that this isn't just true of this beautiful Yamaha piano,
it's true of any regularly constructed, vibrating body,
like the strings on a flute - sorry, the strings on a violin or a guitar.
I'll get to the flute, a vibrating column of air, as in the flute.
Every note produced by those instruments and many others
has embedded within it
this very specific, preordained series of higher notes,
completely dictated by nature.
So, let's try our own experiment
and see if I can get you to hear some of these overtones.
The first one, as I said,
is the result of the string vibrating in two equal parts,
and it's going to be the C an octave above the original C.
If you go back to Maria and the von Trapps,
you remember that we learned our (Plays a C scale),
right? eight notes of the scale,
and every eight notes, we have a repetition of C.
So what I'm going to do is silently depress the key of this higher C.
I'm not playing it, I'm just allowing its strings to vibrate,
and listen to what happens when I strike the lower, fundamental C.
(Plays C)
You hear that higher C?
One more time.
(Plays C)
Everybody hear that? Show of hands.
Who doesn't hear it?
Excellent, amazing.
So the next overtone
is the result of the string vibrating in three equal parts,
and it's going to be a G,
now just five white notes away from that first overtone.
So let's repeat the same experiment.
The tones get fainter as they go up, but listen closely.
I silently depress that G and strike the same fundamental, one more time,
(Plays C)
Hear it? Everybody hear it?
This one's so clear because it's actually a different note.
It's no longer a C, as the first two were;
it's now a new note, a G.
The next overtone continues this trend of diminishing distances between them -
it's now just four white notes up from that G, and it's yet another C.
Let's see if you can hear this one.
It should be quite faint, but let's try the same experiment.
(Plays C)
Everybody hear that?
It's quite faint, but there, right?
And on we go: the next one, just three white notes away, is this E.
It's a new note, so now we have three notes with which to play:
a C, a G and an E.
The one after that is yet another G,
so we're stuck with, still, just three different pitches.
And the next one is interesting;
it falls in the cracks somewhere between A and B-flat.
Now, there's a long and complicated explanation to why that happens,
and it has to do with how modern pianos are tuned,
but for today's purposes,
just remember that sound-wave frequencies
aren't limited to the fixed 88 keys of the piano;
they can occur anywhere,
and so we have our fourth different tone.
Let's recap: we have the original C, the G, the E
and now this beautiful, kind of bluesy color note,
that you can either hear as the lower one with a little bit of upper color
or the upper one with a little bit of color underneath.
The next overtone is another C,
so we still have just four with which to play - it's up here.
And the fifth new note is the very next one in the overtone series,
and it is a D.
So, to recap again:
We have the original C, this G, this E,
this beautiful color A,B-flat and this D.
Five notes.
What happens when I put them all together?
You hear they're all spread out across the piano.
So, here's the C, the D, the E,
the G, and the color A or B-flat.
Now, I'm going to interpret that color note as the lower A,
which is the more common approach.
And, you guessed it,
what we have are the five notes of the pentatonic scale,
(Plays pentatonic scale)
embedded in every single note produced by so many of our instruments.
Now, as such, the pentatonic is one of the true universals in all of music.
You can find it in the folk music of China,
(Chinese folk music)
I know you're dying to try this at home,
so on your piano, it's easy to find the pentatonic scale:
just play all the black keys.
How about as far away as Scotland?
(Music: "Auld Lang Syne")
Same five notes.
Or imagine a pan flute and that we're in the South American Andes.
(Andean Music)
Or how about African or African-American spirituals?
(Music: "Swing Low, Sweet Chariot")
Same pentatonic.
Or how about this one?
(Music: "Amazing Grace")
Same five notes again.
And this turns out to be
one of composers' favorite tools when they try to evoke those cultures.
So here's the French composer Debussy
trying to conjure up the sounds of a Japanese pagoda.
(Music: "Estampes, I. Pagodes")
Or how about a little bit closer to home with Jimi Hendrix?
(Music: "Purple Haze")
Even that one, purely pentatonic.
And we could go on all day.
I haven't given examples from blues or jazz
or Native American music or Greek music.
It really seems like it would be easier to find cultures
that don't use the pentatonic than ones that do.
I don't know if, like me, you've been following the news recently
of these ancient cave discoveries across Europe
and the very fascinating art that was found in them.
Among the artifacts were some prehistoric flutes
dating back 30, 40,000 years,
made from animal bones,
and when those were reconstructed,
it turned out that even some of those were tuned to the pentatonic scale.
So it seems to me that our paleolithic ancestors
have left us a little bit more than just fashionable dieting concepts.
They remind us that whether consciously or subconsciously,
we've been picking up the notes of the harmonic series for millennia
and incorporating it into our diverse musical languages
to the point where they seem so familiar
that a roomful of strangers can reproduce them
just by watching a man jump on stage.
You know, musicians get very excited when they talk about the harmonic series
because it really does hold so many keys
to understanding the way music developed over the course of history.
But for me, one of the most important takeaways has to do with listening,
with real deep, attentive listening,
and I'm not just talking about within the context of music.
There's still a lot for us to discover out there
if we just choose to listen.
Thank you.
(Applause)