Ignite Velocity 2015 (New York, NY)

About this course

so let's talk about tuning a guitar using science because I pretty much do everything using science because science works and the next time you're up on

your in the audience and somebody is up on stage like messing around with their tuning and like in between the song and they're screwing up the strings that are already in tune and you're like God well

they just stop talking and play some music for me you'll know that they're doing it wrong because they're listening to pitch instead of the beats between the notes so there's this interesting

thing about human ear and the way that science works if two notes are close to each other then alternately they cancel out each other and reinforce each other so their magnitude the the amplitude

fluctuates and your ear hears that is a note going kind of wow wow wow wow and this is something pretty cool because it allows you to tune so a little bit of science there's a lot of cool math and

coincidences in music every octave doubles in pitch and then they're divided into these logarithmically spaced 12 semitone divisions and these are all of the notes in it in one octave

but those notes are not pure in other words a note that supposed to be a 440 is not just for 40 it has over tons which are multiples of the base frequency and when notes have ratios

between each other they sound simple and good to our ears and that's because those overtones are almost coinciding with each other they don't quite coincide because math and science and

12th root of 2 and things like that but they almost coincide and you can use those almost coincidences and listen to those over tons if you train your ear and then you can tune your guitar or any

other instrument so these are some of the notes on the guitar and you'll notice that for example 660 and yellow is almost the same as 650 9.26 in yellow and that's exactly the kinds of

relationships that make it possible to tune guitars you can't possibly absorb this line in 15 seconds but if you ever care about it for the future for reference this is what I'm about to show

you how to do so we're going to listen to some of those overtones and see if we can tune a guitar so the first thing I'm going to do in this awesome demo is pull out my tuning fork

so I'm not going to use a nap and what I'm going to do is I'm going to listen to this tuning fork in my head and what I mean here in my head sounds like this 440 cycles a second and then i'm also

going to listen to the overtones in the a string on this guitar and i'm gonna hear the beats he's close enough yeah whatever yeah so here all night so I just tuned to the a

string and then I'm just going to ignore the slides and go ahead because there's plenty of time for this then I'm going to just strike the open strings they sound awful and what I'm really

listening to is the overtones here you can hear them if you listen I'm not going to do this because that's awkward but but that's what you're listening to when you just strike the open strings

and this is the interval here is a fourth and fourths are slightly wide because math and science so I'm going to knit one beat every three seconds wide more or less good

enough for a demo and then the same thing with the D string slightly wide and g string don't worry that I'm getting behind can you hear those beats I don't know if

that's easy for you and then we have a third to throw a wrench into the works and thirds are very wide because math so I need about eight string 8 beats wide and then final fourth

and for this I'm so far off that I don't know when you really screw up the tuning and there we go a metal that will pass most tests