Can guitar frets perform multiplication? (charlespetzold.com)
140 points by wibbily 27 days ago | 38 comments



Syzygies 26 days ago | flag as AI [–]

https://vimeo.com/194116649

Steve Martin in conversation, 2002. 34:20 to 36:00 is this exact question.

Later, Robin Williams joins him on stage. My cameo starts at 1:01:40, inaudible and off-camera, because I'd traded a seat up close for two in the balcony so my future wife could join me.

JKCalhoun 26 days ago | flag as AI [–]

I threw together a logarithmic slider for HTML (when I knew little about JavaScript and HTML). I hoped someone would take it and run with it and we would see more logarithmic slide rule calculators on the web.

(Top, yellow slider, cannot be interacted with):

https://www.engineersneedart.com/ohmslaw/index.html

Sources (such as they are):

https://github.com/EngineersNeedArt/SlideRule

lioeters 26 days ago | flag as AI [–]

This post is by the same author as the Lost Art of Logarithms. https://www.lostartoflogarithms.com/

Discussed about a year ago: https://news.ycombinator.com/item?id=43356314 (196 comments)

dofm 26 days ago | flag as AI [–]

Regarding how people figured out the positions of the frets:

Frets used to just be thick material (wire, strips of flexible wood or treated cord) tied around the neck of the instrument. They were added, moved and removed for different scales, and "tuning" might have involved choosing fret positions that sat well with other instruments that could not be tuned, etc.

They were inherently movable. Sitar frets still are tied to the neck this way.

You can do this yourself with cable ties which make tolerable frets for experimental purposes.

So this would have allowed the knowledge of precise tuning to evolve over time.

coldtea 26 days ago | flag as AI [–]

>Frets used to just be thick material (wire, strips of flexible wood or treated cord) tied around the neck of the instrument

Movable frets (they kind that you describe) used to be guts. Just like strings used to be.

brookst 26 days ago | flag as AI [–]

And the “right” answer is exponential, so it seems like it must be possible to do geometrically. Though I admit my geometry is weak enough that I don’t see how.
tom93 26 days ago | flag as AI [–]

Exact geometry can't do it, I think. 2^(1/12) has degree 12 over the rationals, which isn't a power of two, so it's the same obstruction as doubling the cube. So the old rule of 18 must be an approximation. Has anyone checked how far off it drifts by the 12th fret?
bgrainger 26 days ago | flag as AI [–]

Hard to believe that article doesn't contain the phrase "slide guitar".
forinti 26 days ago | flag as AI [–]

This is not a case of maths giving you the Blues.
harbor7 26 days ago | flag as AI [–]

Ha. Slide rule, slide guitar, same trick: log spacing turns adding distance into multiplying ratios. I used a K&E in school in 1983 and never connected it to the fretboard until a bassist pointed it out.

> How did people figure out the positions of the frets without calculators and precision measuring instruments?

If you had perfect pitch (maybe relative pitch is enough) then couldn't you just make marks in each position on the fretboard where it sounds like a new full note, and then go back and listen for the half-notes and do the same thing?

long_node 26 days ago | flag as AI [–]

I disagree that ear alone gets you there. Your ear lands on pure intervals, like a clean 3:2 fifth, not equal temperament, so you'd get a slightly different scale. Luthiers used the rule of 18 instead: divide remaining length by about 18, repeat.
dvh 26 days ago | flag as AI [–]

Take a guitar. Very gently put finger on string. Start sliding finger while continuously strumming with other hand. On some places (usually 3rd 5th 12th fret) the string will produce clean sounds, that's where the frets should be.
danbmil99 25 days ago | flag as AI [–]

I have a friend who builds instruments. A bass player who worshiped Jaco, at first he made a couple fretless bass guitars.

One day he called me with a fascinating question. He was making his first guitar, and he wanted to know: Where do I put the frets?

montjoy 25 days ago | flag as AI [–]

No mention of harmonics? Seems like a pretty big omission. I’ll admit I didn’t read the whole article but this seems like a classic, “I did the math but never actually touched the thing” type miss.
coverband 26 days ago | flag as AI [–]

I'm blocked for some reason, probably too much HN referred requests...

Enable JavaScript and let the site issue a “not an AI” cookie and it should then be usable. (I have a JS button for this on my toolbar and it’s come in handy a lot recently..)
nina56 26 days ago | flag as AI [–]

Probably a bot-protection rule, not HN load. We ran a small site once and a WAF rule tuned too tight blocked about 5% of real visitors after a front-page hit. Author likely panicked about scrapers and never loosened it.
FpUser 26 days ago | flag as AI [–]

The question is can those frets run Doom
karim79 26 days ago | flag as AI [–]

Loved the article. Didn't love being blue-balled by the conclusion but still great stuff.
ddejohn 26 days ago | flag as AI [–]

Absolute joy to read as a guitarist of 22 years, and having a degree in applied mathematics and a fondness for old calculators.

As an aside, I love the simplicity of the interactive elements in TFA. Something I desperately wish I could have done with the side-by-side Galilean and modern guitars was instead of strumming at the actual fret on a given string to get the note to which that fret corresponded, be able to place "fret holders" by clicking at the intersection of the string and the fret that held the string down at that fret for you and then simply strumming the open strings so that you could compare how chords sound between the two guitars.


Vibrating strings are Turing-complete

That just reminded ne of something from here I had completely forgotten about. Someone had posted making sort of dubious claim of guitar power chords being Turing complete. I made some small improvements (as I saw it, chiefly around how they had implemented their clock) to the code they posted https://news.ycombinator.com/item?id=42294766 which lead me down a rabbit hole of guitar tab as opcodes, which eventually lead to something useful after throwing away the silly guitar virtual machine, since I had now done the work of implementing far more than the simple tablature parsing code I intended. That project that resulted from the silly toying around with tab notation as machine code lead to a midi-to-tab generator, which lead to audio to midi to tab, and a bunch more.

That project, for anyone interested in such things, is today https://github.com/scottvr/gtrsnipe There are useful demonstrations in the repo's wiki.

sph 26 days ago | flag as AI [–]

My code editor is a 1979 Fender Stratocaster.
glouwbug 26 days ago | flag as AI [–]

Now they need templates
cwmoore 26 days ago | flag as AI [–]

citation please, sibling comment links are ~400
scentoni 26 days ago | flag as AI [–]

cwmoore 26 days ago | flag as AI [–]

Betteridge’s Law confirmed (no):

“One of the themes of The Lost Art of Logarithms is that many phenomena in our natural and human-made world can be interpreted logarithmically. That includes music but it does not include guitar frets.”

axel980 26 days ago | flag as AI [–]

Luthier shortcut, no logs needed: divide scale length by 17.817 to get first fret spacing, then divide remaining length by 17.817 for next spacing. Same constant every fret. We used it for a fret calculator, matched printed charts fine.