Vi and Sal Explore How We Think About Scale

[tmn2727]

next time please don't bring her

[Snagabott]

And that is important to remember when you think about history: A lot could have changed in a society between 4670 and 4620 years ago.

[roms4nds]

At 3:43 when Vi draws C ad D, it looks as if she were drawing a happy face. :)

[StudentCommunity]

VIHART AND SALMAN? To quote David After Dentist: Is this real life? :O

[guyboy625]

Perception of forces on limbs is also logarithmic.

[mongoose121212]

Smokin?

[KhanDoubleTime]

Sal does relatively well of the cuff but I know how well Vi does with preparation so I think she should do more.

[freemovies411]

They make each other smarter! I can hear it! :D

As a pianist too, I feel enlightened. ~w~

[GxXTreme]

"I'm going to start doing this at the next party I go to" lmao

[sanrali04]

So, that other triangle is armless...

[marioaleal]

Vi and Sal...Two of my favorite Math People! AMAZING!

[unimaginablyawesome]

..This reminds me of a radiolab episode where they were talking about how babies naturally think logarithmically..

[Saltyember]

was thinking of "plus sized piano keys" too ...till Vi mentioned it then immediately realized how impractical it would be to try to play a chord on Xd but i still want one

[Dwonis]

It's Mr Ug!

[Teeftlis]

yay Vihart

[zoo1619]

We need more collaborations like this, hairs stood up on the back of my neck when I watched this.

[berkk1903]

Wonderful voice vi:)

[Janac]

something about the way she says numbers 0:09

[sjwimmel]

Vi Hart and Salman Khan. A mathematical match made in heaven!

It's exciting just to read that you two work together. It's even more exciting to hear you two interact. It's like you're a catalyst for each other's brain. Seriously, which other two people could come up with a linear piano? Please make more video's together.

Btw. Speed is also sort of logarithmic: When you ride a bike you're going about 2× your walking speed. So in speed: bike≈walk×2, car≈bike×2, train≈car×2.

[dannyboyk2]

I was completely fascinated to learn about the logarithmic nature of piano design--I had no idea! Thank you! :)

[clide8]

For additional interesting talk about numbers and our perceptions of them check out the Radiolab "Numbers" podcast

[Damageinc333]

As a fan of both of you, This video is just awesome. Very entertaining.

[learning112233]

i think you would make awesome couple !!

without miss khan hearing me

[rekilledagain]

My school web approved sites sent me here during school, and all day since I've been home is watching these entertaining and hilarious videos.

[Adronomics]

More of this, please.

[Adronomics]

This is amazing....!

[Orphen01]

C2's frequency is 65.41Hz.

[jfusion10]

Khan should teach Music Theory!

[eagleduzt]

AWESOME AWESOME AWESOME!

[Mozrael7]

WHOOOO HOOOO!!!!! Two most awesome teachers on the Internet together!!! This is mindblowing, just mindblowing.

[catsgodor]

that looks like a pizza slice. :|

it's aaa triiiiiiaaannnnngggggggggggle :D

O.O

[silencedidgood]

I really recommend that Vi, Sal and everyone else take a look at Donald Duck in Mathemagical Land for some reference. Also I believe that each note on the Chromatic scale is related by the 12th root of 2. Go up 12 steps and you get to the doubling they discuss here.

[BraveLittIeToaster]

this is the marvel team up of youtube.

[BGood156]

THE AWESOME! IT BURNS!

[Wodey25]

Gotta say, this could have been MUCH better if Vi told us the real frequencies of those notes rather than just make something up @ 300 hz... The quality overall of this one is well below the standard of Khan Academy videos.

[scottheonly]

I loved this!

[noxure]

The base frequencies of the keys on a piano go from somewhere between 20Hz and 6.000Hz. It's the orchestral instrument with the widest range and a top quality winged piano is almost impossible to record accurately.

[JackExYou]

Vihart and Khanacademy are the only two channels I subscribe to. Suddenly they make video together? Damn. A match made in math and music heaven.

[stephenhorton]

love it. You're parties must be fascinating, bringing that out as one of your party games! I really like the videos with two people, they seem a lot more relaxed :¬) Thanks for the video :¬)

[56jmoney]

Who is this Vi woman? Is she single? Oh, sorry... is she childless and single?

[SonOfNye]

@56jmoney She is the woman that the math nerds of youtube pine for.

[lnr08f]

omg she sounds so hot. I'm only 20 seconds in too ha definitely subbing to her

[ADAM1989VST]

I think this is a cool example; Everyone perceives a 20 yr old to be much older than a 15 year old, but everyone feels that a 55 yr old is around the same as a 50 yr old...

...I think that's a good example anyway. like, you would never hear a 55 yr old say to a 50 yr old "shut up! i'm older than you!"

[out2of2this2world]

oh my if they get together and have kids their kids would be so awesome the world would collapse!!

[KevZyro]

@out2of2this2world

Sal is married

[out2of2this2world]

@KevZyro that doesnt stop some people

[fritstoofvlees]

do you nail her?

[TheGstar1985]

@fritstoofvlees lol

[greeny202a]

Is it me or does Vi sound really hot?????

[intellegence63smart]

@greeny202a Vi is Asian by the way.

[intellegence63smart]

@greeny202a Or she's Caucasion. 

[IshDat1KiD]

@intellegence63smart

Vi is definitely, a Vietnamese name.

[IshDat1KiD]

@intellegence63smart

But, according to her page.. she's white.

[intellegence63smart]

@greeny202a Vi is Sal's girlfriend.

[greeny202a]

@intellegence63smart Well I'm pleased for them both but the fact remains she has a hot voice. Maybe its because I'm from England LOL. Then again I find the deep South American accent hot too (Texas)! Maybe I'm just sick ha ha ha

[intellegence63smart]

@greeny202a lol hahaha, it's not just you :P

[NewgroundsOwnSBB]

@intellegence63smart except no

[intellegence63smart]

@NewgroundsOwnSBB how come?

[kevinquinnyo]

look at a guitar fretboard! i'm too lazy to check if anyone's already pointed this out... but the fret distance starts fat, and ends smaller and smaller

[shashi2469]

sal & vi are awefun! By the way sal do you speak 'Bengali'?

[kaninepete]

Sal and Vi are literally my favorite two people!!

Except for my wife :)

[musicmathchris]

Nicely done - I've always told my students that there are interesting links between music and math. This gave a nice clear explanation.

[ratuliut]

Our color perception is also nonlinear.

[josefgiven]

get a room you two ;)

[KhanNorwegian]

How about the guitar? The low F fret is double the width of the F one octave higher. Is that related to the logarithmic scale? Or is that an example of an instrument made after linear scales?

[NewgroundsOwnSBB]

@KhanNorwegian yeah that must necessarily be linear (since you're modifying the pitch by essentially shortening the part of the string that's vibrating when you hold down the pitch). You can see that the distance between the 12th fret and the 24th fret is exactly half the distance between the nut and the 12th fret for example. Pianos have different strings for every single note so they can make it like they do.

[shinimog]

@KhanNorwegian What you hear is logarithmic, but in order to actually generate the sound, it has to be linear, hence the 'fat key' piano example. in essence, a guitar is a poor man's fat key piano

[agricolaterrae]

It's nice to see my two favorite math tutors have finally teamed up.

[caruccio]

Vi and Sal? Looks like to text editors from unix to me ;P

[MyOverflow]

@caruccio All we need now is someone named pico to come in.

[Orygyn]

Middle C = 261.626 Hz

[likeprestige]

awesome!

[Wedidurmom]

She sounds horny !

[griftorifto2]

These past three videos were amazing.

[griftorifto2]

@jdnovanford base 2

[Jdonovanford]

Logathimic scale but in which base? Is always base 2 or base 10, or...?

[tautologicalnickname]

@Jdonovanford for octaves it's base 2 she said i think

[Jdonovanford]

She's bad! Fire her, Sal!!!

[hedonism13]

:O

ViHart?!

*dies from awesomeness overload*

[bulletfanmhdan]

Sal, you must go to some awesome parties!! Aha

[UltraMaXAtAXX]

I'm sure Vi was trying to get at A440 (440 Hz, the A below middle C).

[Parthematics]

This is bullshit!!!!!!!!!! fire her sal!!!

[Shadowriku40]

MUSIC YES YES YES

I'm in love with you, Sal. <3

[davetoms1]

Link to Vi's channel in the description, please?

[kh103y]

@davetoms1 just youtube vihart.

[davetoms1]

@kh103y I already subscribe to her. I'm asking on behalf of the masses who can't / don't bother to work harder than click a link :P

[kh103y]

@davetoms1 ah fair enough ;) thats very nice of you :P

[dwees2]

@davetoms1 Her Youtube account is Youtube.com / Vihart

[davetoms1]

@dwees2 lol thanks, I subscribed to her long ago. I asked on behalf of the masses who can't / don't put any more effort into things than a click :)

[goldenoj]

Keep the same width keys, but divide into finer and finer partitions. That'd be new wave.

[MoGaDeX]

Its not really about how we think of it, but how we perceive scale and numbers. I personally never had a problem with scales.

[thmstbst]

OK i wanna figure out the frequency difference between middle c and d compaired to the difference of  the frequency between the next octave c and d !

so, lets map out what we know

C2 = C1 * 2

C1 = 600

C2 = 1200

and there are 7? keys of difference between C1 and C2

i have no idea what to do next

[BrickInTheWall1]

@thmstbst There are 12 notes/keys which make the difference between an octave (same letter name). The reason that they are grouped in 7 is to do with musical 'scales' which are common patterns of notes more to do with natural resonances or a harmonic series (more a physics problem). Anyway, so in equal temperament tuning, which is used for pianos, the difference between the letter names is as you've shown:

C2 = C1 * 2

but the difference between C and D is 2 notes, not one. a better example is...

[BrickInTheWall1]

@BrickInTheWall1 Between (B and C) or (E and F) because they're one note apart.

There are a couple of ways you can do it:

For equal temperament, you take the frequency of the first note e.g. the B below middle C, which is 246.942 Hz.

You multiply that by 2^(1/12) and you get the next note up.

A good approximation is multiplying the frequency by (16/15). This gets you close, but not exact answers.

There are other formulas/approximations for the other notes if you're interested.

[CobraCommandurr]

.....

[vibol03]

when i saw the piano in the thumbnail, i thought you were going into music teaching

[Ibahz]

@vibol03 Haha yeah i thought the same thing

[jabberwocky685]

yaay i love both of your videos

[sandwichperson]

Pretty sure it's illegal to have this much awesome+smart in one video.

[AdmiralJef]

VIHART AND SAL AAHHHHHHH

[PaperSpock]

I love it! Two of my favorite YouTube intellectual types get together! Best crossover in the history of best crossovers!

[mTucci]

If you look at a guitar fret board, it is easier to see these distances between octaves.

[CompulsiveOrigami]

@mTucci Although there are very many octave shapes on the fretboard. 

[mTucci]

@CompulsiveOrigami I should have clarified, I meant on a single string

[Nightrain602]

LOL she's silly (:

[thelateoscar]

finally music class at the khan academy :D \m/

[ataraxic89]

lol If you dont know Viheart then you must be sad people, check her out on youtube. She's wonderful and I keep asking her to marry me. No response.

[funnybleh]

try vihart.org and find out.

[gumdrops27]

The girl sounds very familiar. Sounds like my teacher from music camp.

[dudeB15]

who is this girl?



[dudeB15]

@dudeB15 she kinda sucks

[MultiRationale]

i find it fascinating as well as shocking to see different personalities, that i know, collaborating. makes one realize how closer we are than we think.

[xAnimeChannel]

@dudeB15 Vihart awesome mathematician and musician she has a you tube account

[91jgphonecall]

havent even seen the video yet but fuckyeah!

[rlewis1946]

Please introduce Vi to us...

Roy Lewis Atlanta, Georgia USA

[werdnativ]

Wow! I'm excited to see Vi working with Khan! I sure hope there will be more to come!

[DivergentMind]

I'm glad to see this collaboration.

[stereoarchitect]

stoner ha thats a compliment

[musicgenius100]

1st