4 ms·

Plotting patterns in music with a fantasy record player

152 points by erikschoster 6y ago

jcims 6y ago
Feast - http://www.windytan.com/p/posts.html http://www.windytan.com/p/posts.html She's a beast.
- th0ma5 6y ago
  Picking out GPS coordinates from the recording of a news helicopter was astounding.
tasty_freeze 6y ago
I recall reading many years ago (20?) about a classical music afficianado with a unique ability that was really only useful at impressing other people at parties. He could tell what record he was looking at by sight by inspecting the groove patterns: number of tracks, track length, and even the patterns of the active part of the song itself. As I recall, he was proud that he once identified the 1812 overture from more than 10 feet away because of the placement of the grooves at the loud parts. BTW, records didn't necessarily have constant spacing -- the cutter knew the amplitude of the part of the spiral plus/minus one rotation away so it could place the track close as possible without causing collisions. I believe that made it easier to identify songs.
- noyesno 6y ago
  Maybe you are remembering Dr. Lintgen? https://www.snopes.com/fact-check/the-record-reader/ https://www.snopes.com/fact-check/the-record-reader/ "Dr. Arthur Lintgen, a Philadelphia physician, can — within prescribed limits — determine which works of classical music are present on a phonograph record by “reading” the record’s grooves. His ability is not the result of any trickery — he performs the feat by combining a thorough knowledge of classical music with the technique of determining the structure and dynamics of a piece of music by examining the spacing and pattern of the grooves."
- Vivtek 6y ago
  Doug Hofstadter has written about that, I believe. It definitely sounds Hofstadterian, anyway.
the_cat_kittles 6y ago
god DAMN this is a fun post. i love it, and i have nothing to add other than thank you
082349872349872 6y ago
I remember working at a place that had sun-diffusing window shades with a grid of small holes in them. Walking from the elevators to my cubicle (I was only a summer intern, and hence had a cube, not an office) in the morning, I was greeted by an interesting interference pattern: there would be a counter grid of "dark spots", which unlike physical spots appeared large when one was far and got smaller as one approached...
- th0ma5 6y ago
  We have some shades similar to that I have used them to visualize the partial eclipse with coworkers.
  - pault 6y ago
    I noticed during the last local eclipse that the light shining through the trees cast thousands of little eclipses on the ground. I thought it was way cooler than the eclipse itself.
- jcims 6y ago
  Like this? https://www.inverse.com/article/41595-hermann-grid-illusion-black-dot https://www.inverse.com/article/41595-hermann-grid-illusion-... (Scroll down)
  - 082349872349872 6y ago
    I think more of a Moiré...
skinkestek 6y ago
Ah. Finally! Used to follow Oona on Google+, but forgot the name and haven't had a (working) RSS setup for the last few years so I hadn't read anything from her since then. She's totally amazing when it comes to decoding signals, noticing effects and naming them (for example: there's a video on her YouTube channel with her filming a brick wall as she goes towards and back from a brick wall and she points out how the sound of a nearby waterfall changes.)
- DanBC 6y ago
  For people who are interested: https://www.youtube.com/watch?v=Amj4UevyRfU https://www.youtube.com/watch?v=Amj4UevyRfU
dclowd9901 6y ago
Very cool, but the 3D illustration is off. Unless that record play speed is continuously variable, the aligned beats that come later in the animation should have a spiral-like pattern, otherwise the innermost rings would have a far faster rhythm. Incidentally, a lot of sound engineers at the time would put tracks with less frequency dynamicism into those innermost rings to prevent records from skipping.
- radiowave 6y ago
  I don't follow you. The musical pattern repeats over a fixed length of time, and the turntable completes one rotation within the same length of time. How would that produce a faster rhythm in the innermost rings, absent a spiral?
- zuminator 6y ago
  > otherwise the innermost rings would have a far faster rhythm. Think that over. On a 33 1/3 LP, the outermost groove takes 1.8 seconds to complete a rotation. The innermost groove takes... 1.8 seconds to complete a rotation. Hence, over the entire record, every single groove lines encodes 1.8 seconds of information and lines up exactly with its neighbor in terms of time elapsed. The inner grooves have less space to cover but they compensate by moving more slowly. It's weird but makes sense in a way that's reminiscent of Aristotle's wheel paradox ( https://en.wikipedia.org/wiki/Aristotle%27s_wheel_paradox https://en.wikipedia.org/wiki/Aristotle%27s_wheel_paradox ) On a perfectly mastered LP, any song whose bpm is a multiple of 33 1/3 would have these lined up rhythmic patterns. E.g. a song that clocks in at 100 bpm would have exactly 3 beats in every rotation. You could make a faster dance song line up by speeding up the motor to a fractional degree. >Incidentally, a lot of sound engineers at the time would put tracks with less frequency dynamicism into those innermost rings to prevent records from skipping. True, since the innermost grooves have less space to encode information, they have to wobble more in a given distance in order to maintain the same dynamic range. IIRC sometimes they would space those inner grooves further apart to give them more wobble room.
rland 6y ago
Neat, this reminds me of https://www.math.uci.edu/~isik/posts/Eigentechno.html https://www.math.uci.edu/~isik/posts/Eigentechno.html (hn post https://news.ycombinator.com/item?id=24820824 https://news.ycombinator.com/item?id=24820824)
- acomjean 6y ago
  it reminds me of the "Woz a day" disc images, though not music related. https://twitter.com/a2_4am/status/1022258525962219525 https://twitter.com/a2_4am/status/1022258525962219525

152 points by erikschoster 6y ago

jcims 6y ago

Feast - http://www.windytan.com/p/posts.html http://www.windytan.com/p/posts.html She's a beast.

th0ma5 6y ago
Picking out GPS coordinates from the recording of a news helicopter was astounding.

tasty_freeze 6y ago

I recall reading many years ago (20?) about a classical music afficianado with a unique ability that was really only useful at impressing other people at parties. He could tell what record he was looking at by sight by inspecting the groove patterns: number of tracks, track length, and even the patterns of the active part of the song itself. As I recall, he was proud that he once identified the 1812 overture from more than 10 feet away because of the placement of the grooves at the loud parts. BTW, records didn't necessarily have constant spacing -- the cutter knew the amplitude of the part of the spiral plus/minus one rotation away so it could place the track close as possible without causing collisions. I believe that made it easier to identify songs.

noyesno 6y ago
Maybe you are remembering Dr. Lintgen? https://www.snopes.com/fact-check/the-record-reader/ https://www.snopes.com/fact-check/the-record-reader/ "Dr. Arthur Lintgen, a Philadelphia physician, can — within prescribed limits — determine which works of classical music are present on a phonograph record by “reading” the record’s grooves. His ability is not the result of any trickery — he performs the feat by combining a thorough knowledge of classical music with the technique of determining the structure and dynamics of a piece of music by examining the spacing and pattern of the grooves."
Vivtek 6y ago
Doug Hofstadter has written about that, I believe. It definitely sounds Hofstadterian, anyway.

the_cat_kittles 6y ago

god DAMN this is a fun post. i love it, and i have nothing to add other than thank you

082349872349872 6y ago

I remember working at a place that had sun-diffusing window shades with a grid of small holes in them. Walking from the elevators to my cubicle (I was only a summer intern, and hence had a cube, not an office) in the morning, I was greeted by an interesting interference pattern: there would be a counter grid of "dark spots", which unlike physical spots appeared large when one was far and got smaller as one approached...

th0ma5 6y ago
We have some shades similar to that I have used them to visualize the partial eclipse with coworkers.
- pault 6y ago
  I noticed during the last local eclipse that the light shining through the trees cast thousands of little eclipses on the ground. I thought it was way cooler than the eclipse itself.
jcims 6y ago
Like this? https://www.inverse.com/article/41595-hermann-grid-illusion-black-dot https://www.inverse.com/article/41595-hermann-grid-illusion-... (Scroll down)
- 082349872349872 6y ago
  I think more of a Moiré...

skinkestek 6y ago

Ah. Finally! Used to follow Oona on Google+, but forgot the name and haven't had a (working) RSS setup for the last few years so I hadn't read anything from her since then. She's totally amazing when it comes to decoding signals, noticing effects and naming them (for example: there's a video on her YouTube channel with her filming a brick wall as she goes towards and back from a brick wall and she points out how the sound of a nearby waterfall changes.)

DanBC 6y ago
For people who are interested: https://www.youtube.com/watch?v=Amj4UevyRfU https://www.youtube.com/watch?v=Amj4UevyRfU

dclowd9901 6y ago

Very cool, but the 3D illustration is off. Unless that record play speed is continuously variable, the aligned beats that come later in the animation should have a spiral-like pattern, otherwise the innermost rings would have a far faster rhythm. Incidentally, a lot of sound engineers at the time would put tracks with less frequency dynamicism into those innermost rings to prevent records from skipping.

radiowave 6y ago
I don't follow you. The musical pattern repeats over a fixed length of time, and the turntable completes one rotation within the same length of time. How would that produce a faster rhythm in the innermost rings, absent a spiral?
zuminator 6y ago
> otherwise the innermost rings would have a far faster rhythm. Think that over. On a 33 1/3 LP, the outermost groove takes 1.8 seconds to complete a rotation. The innermost groove takes... 1.8 seconds to complete a rotation. Hence, over the entire record, every single groove lines encodes 1.8 seconds of information and lines up exactly with its neighbor in terms of time elapsed. The inner grooves have less space to cover but they compensate by moving more slowly. It's weird but makes sense in a way that's reminiscent of Aristotle's wheel paradox ( https://en.wikipedia.org/wiki/Aristotle%27s_wheel_paradox https://en.wikipedia.org/wiki/Aristotle%27s_wheel_paradox ) On a perfectly mastered LP, any song whose bpm is a multiple of 33 1/3 would have these lined up rhythmic patterns. E.g. a song that clocks in at 100 bpm would have exactly 3 beats in every rotation. You could make a faster dance song line up by speeding up the motor to a fractional degree. >Incidentally, a lot of sound engineers at the time would put tracks with less frequency dynamicism into those innermost rings to prevent records from skipping. True, since the innermost grooves have less space to encode information, they have to wobble more in a given distance in order to maintain the same dynamic range. IIRC sometimes they would space those inner grooves further apart to give them more wobble room.

rland 6y ago

Neat, this reminds me of https://www.math.uci.edu/~isik/posts/Eigentechno.html https://www.math.uci.edu/~isik/posts/Eigentechno.html (hn post https://news.ycombinator.com/item?id=24820824 https://news.ycombinator.com/item?id=24820824)

acomjean 6y ago
it reminds me of the "Woz a day" disc images, though not music related. https://twitter.com/a2_4am/status/1022258525962219525 https://twitter.com/a2_4am/status/1022258525962219525