(dynamic music) - Good afternoon, everyone.

My name is Sarah Hicks, and welcome to Minnesota Orchestra's Young People's Concert, the Science of Sound.

Science is all around us and touches everything in our lives, even here on stage.

Today, our amazing friends from the Science Museum of Minnesota are going to help us understand the science behind the sound of the music we play.

A few members of the orchestra visited the Science Museum, and they learned so much.

We'll join them on this journey of discovery.

So let's begin with a very important question.

What exactly is sound?

Let's take a look and a listen.

(gentle music) - So what is sound?

Sound is the vibration moving through the air in waves.

- Think of sound as a wave.

All instruments make their own waves.

(cello music) - Can we actually see how sound waves work?

Hi, Janet.

- Hi, Lovrick, hi, Esther.

- Hi, Janet.

- Welcome to the Wave Tank at the Science Museum of Minnesota.

Now we can't see sound waves, but we can observe them with our ears.

And scientists have recorded and measured them, so we know they exist.

And so imagine that sound waves come from your instrument and ripple through the air to your audience's ears.

- That's amazing.

How does this machine work exactly?

- Well, this machine works very similarly to the way sound waves are created by your instruments.

The water is pushed, creating a longitudinal wave, and you can see that some of the waves are long, but they could be short, they could be high, or they could be low.

- Can you change the waves?

- Yes, you can.

You can change the waves by the sound you make on your instrument.

- That's really interesting, and it reminds me a lot of my cello.

Whenever I pluck the string or bow the string, the string vibrates side to side, and depending on how it vibrates, it creates different types of sound waves, different shapes and sizes.

And so this is a great way to see that.

- On the trombone, the buzz is created with the lips and then into the mouthpiece and then out through the instrument creates the sound.

- Wow, I'm just imagining that sound coming from your instrument, all those waves trickling through.

And this is a great illustration of what sound waves look like.

- So vibrations produce a wave that travels through the air, and when these vibrations hit our ears, our brains translate them into sound.

As we perform our next piece by Robert Schumann, I'd like you to listen for the sounds of many different instruments, and as you listen, think about the vibrations traveling into our ears and how the sounds of these different instruments and their different sound waves interact and blend together.

Here now is the third movement from Schumann's "Symphony Number Three."

(mellow music) (elegant music) - Sounds are everywhere, made by people, animals, the environment.

So how are we able to hear sounds the way we do?

Hi, Kim.

- Hey, Esther.

Here at the Science Museum of Minnesota, we have an exhibit called Waves on a String.

When we hear a note, we hear its frequency, and we are actually gonna be able to see the frequency as well.

It has to do with how short or long the wavelengths are.

- Awesome.

So here's the lower note.

(low cello music) - Did you notice what those lines were doing?

- [Esther] Yeah, they were pretty wide and tall.

- Yeah, that's because when you have a lower-pitch note, it has a low frequency, and that means that those wavelengths are longer and they don't repeat as often.

- Okay, so I'll try a higher note now.

(high cello music) - Did you see the difference this time?

- Yeah, definitely.

A lot smaller and a lot closer together.

- That's because that note had a higher frequency.

That means that those wavelengths were shorter and they repeated a lot more.

- Gotcha, that's awesome.

Well, I was wondering if we could try this on my cello.

- That'd be great.

(low cello music) That note had a really low pitch.

What were you doing to make that happen?

- So I was actually stopping the string, so I was pressing my finger down.

And I'm on the lowest string, which is the C string, and I'm playing close to the scroll, which makes that low pitch.

- Can you show us a note with a high pitch?

(high cello music) How did you do that?

So if you notice, now, instead of being on the lowest string and close to the scroll, I was on the highest string and closer to the bridge, which is this wooden piece right here.

- So that made it have a higher frequency, so the note we heard had a higher pitch?

- Yup.

So when you're actually listening to music, you're really just hearing a bunch of sounds coming together to make that music.

- Thank you.

- Our brains translate different frequencies into different pitches, which composers put together to create melodies.

Sometimes melodies are easy for us to sing, and other times they're really complicated.

Our next piece is full of all kinds of melodies using a wide range of pitches, sometimes low, sometimes very, very high, and sometimes somewhere in the middle, and they all feel different to all of us.

Let's welcome our guest soloist, Catherine Carson, a sophomore at the Eastman School of Music, who will play the last movement of the Sibelius "Violin Concerto."

(feet stamping) (suspenseful music) (feet stamping) (audience applauding) (percussion music) - What you're hearing when I strike the drum is the sound waves from the drum rippling through the air.

(percussion music) As I get louder, those sound waves change in height.

Let's see how the science behind the sound works.

Hi, Janet.

- Hi, Kevin.

Your drum is really loud.

When I listen to music, I can control the volume.

How do you control the volume on your drum?

- Well, when I play music, I control the volume or the dynamics by changing the force with which I hit the drum.

The easiest way for me to do that is to change the stick height.

When I come from a high place, there's more acceleration into the drumhead and therefore more force.

When I come from a low place, it's less acceleration and less force.

(percussion music) - Okay, so the higher your sticks are, the more energy and force they put into the drum, and so that creates a higher amplitude.

- Yes.

- Scientists and engineers can measure that using an oscilloscope and a decibel meter.

Can you play something that we can measure?

- Sure.

(percussion music) - Oh, is there another reason that you hit the drum harder?

- Yeah, sometimes composers ask us to play off stage, so the sound is more muted and distant.

But when we play farther away, we play louder so that the sound can travel across the stage, through the music, and still reach the audience in the back of the hall.

- What we know then is that a higher amplitude sound will travel farther.

We can experience this amplitude by using body percussion.

Could you clap a rhythm out for us and let's hear the difference?

(Kevin clapping) - That kind of stings actually.

I can feel the energy.

- Yeah.

- If I clap softer, (claps) I can feel I'm using a lot less energy.

- Okay, thanks, Kevin.

- You're welcome.

- Dynamics or differences in volume are another great way in which composers express their ideas and make music interesting for us to listen to and perform.

Listen to how Brahms uses contrasting dynamics in the next piece and how those dynamics make you feel.

Do you feel loud dynamics and soft dynamics in different parts of your body?

Let's hear Brahms' "Hungarian Dance Number Five" and find out.

(vivacious music) (solemn music) - What Lovrick and I just played was a demonstration of different intervals, consonant intervals and dissonant intervals.

- When notes that are played together and blend together well, those are called consonant intervals.

(melodious music) - And when notes are distantly related, they do not blend together as well, and they are called dissonant intervals.

(dissonant music) Here's a way to actually see the difference.

Hi, Kim.

- Hey, Andy, hey, Lovrick.

With this Musical Ratios exhibit here at the museum, we can actually see what those sound waves might look like.

Want to check it out?

- Yeah!

- Yeah!

- Okay, when I play a note, (piano music) we can see the sound wave show up on this oscilloscope.

- Yeah.

- Do you want to try a consonant interval for us?

- [Lovrick] Sure.

- Can you play lower C and a higher C?

(piano music) - [Andy] Look at that.

That's cool.

- Yeah.

Those waves almost seemed to meet up.

Did you notice that?

- Yeah.

- That's because those two Cs are the same note.

One's just at a higher frequency.

So they're actually perfectly consonant.

- Yeah.

- How about you, Andy?

Do you want to try one?

- [Andy] Absolutely.

- [Kim] Can you try F and B?

- [Andy] Okay.

(piano music) - So because that was a dissonant interval, the sound waves didn't meet up at all and they kind of seemed to bump into each other.

- Yeah.

- Lovrick, what kind of intervals do you play the most in music?

- I'd say more often than not I play consonant intervals.

- Then why do we need the dissonant intervals too?

- Well, all I can think of is that when we're playing, every time it was on a dissonant interval, my face, my body wanted that next interval to happen.

I think composers use all those intervals to express that feeling to the audience at large.

- I am gonna listen for consonant and dissonant intervals next time I listen to some music and see how they make me feel.

- [Andy] Yeah, absolutely.

- It was really interesting to see how different notes interact with each other.

We've instinctively learned to feel this tension when we hear dissonance and expect it to resolve to consonance.

Composers use these expectations to create a sense of motion in music.

Tchaikovsky opens this next piece with a back and forth between the trumpets and the orchestra.

The trumpets play the same note every time, but the orchestra moves from consonant to dissonant chords.

I want you to notice how these chords make you feel and where you think the music wants to go.

I find that my body tends to lean forward or tighten up as we lead to that consonant chord, so I'd like you to pay attention to see how your body reacts to this next piece.

It's a polonaise by Peter Ilyich Tchaikovsky.

(stately music) So far we've learned a lot about how sound works, but there's one more question I have.

Why is it that different instruments like a violin and a trumpet sound so different even if they're playing the same note?

Well, we sent two members of the orchestra to find out.

(pensive music) - We've just heard the way the same music can sound different when it's played by another instrument.

We use the word timbre to talk about sound quality or tone color.

I would describe the timbre of the flute as clear and light.

- And I would describe the timbre of the bassoon like a warm, soft, fuzzy blanket.

Some people would also say below and mellow.

Now let's see why these instruments sound so different.

- Hey, Chris, hey, Roma.

- Hi, Kim.

- Hi, Kim.

- Why is it important to have instruments with different timbres in the orchestra, Chris?

- Well, I think that's what makes it interesting to come and listen to and to hear.

If everything sounded the same, I think you would get really bored really quickly.

- Just like when we have a group of people, we all have our own individual voice, we all sound a little bit different, it's the same thing with a group of instruments.

Each instrument has its own voice.

- That makes a lot of sense.

Well, I have a science demonstration that I can do to let us hear how the timbre of an instrument can be changed by the material it's made of.

Do you want to hear it?

- Yeah.

- Yeah.

- I have two bottles here.

One is glass.

(low bottle whistling) And one is plastic.

(high bottle whistling) Could you hear the difference with those?

- [Roma] Mm-hmm.

- Well, I know there are a lot of instruments that are made from wood.

Chris, is your bassoon made from wood?

- My bassoon is actually made out of a very specific kind of wood, a maple tree.

They do make bassoons made out of different kinds of wood, and they even make bassoons made out of plastic.

- Roma, what's your flute made of?

- My flute is made out of gold, and I also brought a silver flute today because that's what you're going to see the most of.

The silver one is gonna be a little bit brighter and project a little bit more.

The gold one is going to be a little bit richer sound, a little bit darker.

- Besides the material of an instrument, the size of an instrument can also affect its timbre.

- So I also brought my piccolo with me today.

You can see it's very different in size from my flutes.

The piccolo is the smallest instrument that we have in the orchestra, and so it's going to sound the highest.

(high piccolo music) - Well, thank you both for helping us demonstrate this today.

- Thank you.

- Thank you.

- Timbre is one more tool in a composer's toolkit.

We can hear the same melody from different instruments or combinations of instruments and feel different things.

The two instruments from the woodwind family we just heard sounded really different.

So imagine the many instruments of an orchestra combining to create countless unique timbres, which is just what our next composer does.

Listen to how he uses different families and instruments of the orchestra and all the incredible effects that produces.

This is movement one called "Varoom" from "Symphony Number One" by Kenji Bunch.

(vibrant music) (lilting music) - We enjoyed meeting the musicians from the Minnesota Orchestra today in the exhibit hall.

- We got to see the science of sound in action.

- [Janet] You can explore sound at home using the materials around you.

- You can make a string instrument with just an open container and a rubber band.

When you put the rubber band over your container and pluck it, (band twangs) it makes a noise.

- Here are some examples using different sized rubber bands.

(bands twanging) Or an example with the same rubber band, but stretched to different lengths.

(bands twanging) - [Kim] Let's try mine.

(bands twanging) Those sounded really different.

That shows us how the material you use can also make a difference.

- Once you're done making string instruments, you can explore percussion.

Check out your kitchen for some utensils to strike different objects.

(utensil clanging) (gentle instrumental music) - As you experiment at home, you can imagine the sound waves rippling through the air.

- Thank you to our friends at the Science Museum of Minnesota for helping us explore the science of sound today.

We also had a chance to see how composers use some of these elements, vibration, frequency, amplitude, dissonance, consonance, and timbre, to write music and to communicate to us.

I hope that you'll keep discovering new sounds and experimenting with different ways to make music, just like all of these composers did.

And when you have the opportunity to choose which instruments you want to play, you can use your new scientific knowledge to make the best choice for you.

But for now, we have one last piece of music for you, Jennifer Higdon's "Peachtree Street" from the "City Scape."

And as you listen, I hope you'll think about all the elements of sound we talked about today.

Thanks so much for joining us on our musical and scientific journey, and we'll look forward to seeing you next time.

And for now, here is "Peachtree Street."

(stirring music) (elegant music) Woo-hoo!