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The Geometry of Music

An anonymous reader notes a Time.com profile of Princeton University music theorist Dmitri Tymoczko, who has applied some string-theory math to the study of music and found that all possible chordal music can be represented in a higher-dimensional space. His research was published last year in Science — it was the first paper on music theory they ever ran. The paper and background material, including movies, can be viewed at Tymoczko's site.

28 of 170 comments (clear)

  1. Hmmmm. by jd · · Score: 4, Insightful

    Neanderthals had flutes and discovered the octave. If we are to assume music is linked to string theory, then the problem of where they all went is solved! They were the aliens all the time! (Seriously, the paper is interesting, but you can always describe a simple system with a complex one. I'd want solid evidence that this is the reduced form.)

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    1. Re:Hmmmm. by espiesior · · Score: 5, Insightful

      The wording is quite misleading. Tymoczko used "string theory" math... i.e. Geometric Topology (the article tries to play with "orbifolds" - fancy manifolds). Doesn't mean that string theory and music theory are intrinsically related in the physical world (which they are for the obvious OTHER reason), but rather, they can be expressed by the same monsters in the world of mathematics.

    2. Re:Hmmmm. by TapeCutter · · Score: 3, Funny

      "I'd want solid evidence"

      Yeah, Science will print any crackpot theory...oh wait...dammit...I've conflated Slashdot and Science, again! Second time this week...

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
  2. The Naked Scientist by DKlineburg · · Score: 4, Interesting

    The Naked Scientist actully just had a Podcast [MP3 Link] about music and science. If you find music and science interesting, I think it is a good listen. Not quite on the string theory level, but non the less I think it is relivant.

    --
    Memory is deceptive because it is colored by today's events. - Albert Einstein
  3. Actually by El+Lobo · · Score: 5, Interesting

    It's not the first time music has been represemted as mathematical equations, or even as a random events. Hell, even Bach experimented by throwing a pair of dices while composing some of his most popular baroque parts.

    --
    It's time to realise that Abble's products are the biggest abomination these days. Just say NO to the dumb iAbble way!!
    1. Re:Actually by Yetihehe · · Score: 4, Informative

      Mathematical equations can be stochastic, they may have defined certain probabilities of happening. Stochastic L-Systems are good for demonstrating outcomes of some stochastic equations (I'm telling it after weekend with L-system parser for school project).

      --
      Extreme Programming - Redundant Array of Inexpensive Developers
    2. Re:Actually by El+Yanqui · · Score: 3, Funny

      Dice, shmice. More cowbell is all that's needed to solve the equation.

      --
      Well, thanks to the Internet, I'm now bored with sex.
    3. Re:Actually by baldass_newbie · · Score: 4, Insightful

      It's not the first time music has been represemted as mathematical equations

      You're right. Plato did it in the Timaeus about 2500 years ago.
      It's nice to see folks eschewing traditional Western culture and then 'discovering' things the same Western tradition developed over two millenia ago.
      --
      The opposite of progress is congress
  4. Dirk Gently by freaknl · · Score: 5, Funny

    Am I the only one who immediately thought of the computer scientist in Douglas Adams' Dirk Gently's Holistic Detective Agency?

    1. Re:Dirk Gently by Decameron81 · · Score: 4, Funny

      Am I the only one who immediately thought of the computer scientist in Douglas Adams' Dirk Gently's Holistic Detective Agency?


      Yes.
      --
      diegoT
  5. one suggestion.. by unfunk · · Score: 4, Interesting

    ...instead of having to play some of my own compositions on my nonexistent MIDI keyboard (my only MIDI device is my guitar amp effects controller), or manually entering the chords one by one, how about giving us the option to directly open MIDI files? MIDI files can be found for just about every equally-tempered piece of music you can think of, and it would be very interesting to see what they "look" like.

    Also, as a composer myself, I'd like to be able to see what they look like :)

  6. Seems to me by Smordnys+s'regrepsA · · Score: 3, Funny

    Lots of people found out exactly this in the sixties.

    ...or, maybe it wasn't the music, but the copious amount of hallucinogens that were taking them to higher dimensions.

    --
    Just -1, Troll talking to another.
  7. but this goes for any stream of information by jacquesm · · Score: 3, Insightful

    not to belittle the guys achievements, but isn't it so that any sequence of bits can be represented by any arbitrary higher dimensional space ?

    The difficulty usually comes when trying to describe a higher dimensional space in a system with *less* dimensions, the other way around is trivial.

    1. Re:but this goes for any stream of information by Bjarke+Roune · · Score: 3, Insightful

      It is often true that if you have some parametrized way for describing data, then you generally want as few parameters as possible. You definitely want fewer parameters than data points, so going to more parameters or dimensions is not an achievement, as you point out.

      The article is light on mathematical details, but it seems that the achievement is that this space of points has been characterized in a useful way. The story is not that now it can be done with even more dimensions (which as you point out would be trivial). Rather, the story is that now this space of points has been characterized at all, and this description just so happened to require several or many dimensions.

      Since this paper is the first ever on musical theory to be published in Science, which is a highly prestigious peer-reviewed journal, we can assume that the paper is saying something interesting within its field. Specifically, we can assume that this is not just a question of fitting some standard statistical model to some data points.

    2. Re:but this goes for any stream of information by Sage+Gaspar · · Score: 3, Interesting

      He essentially came up with (or used someone else's) model for putting some sort of measure of distance on music, then studied its phase space, which is minimal in dimension.

      For example consider the space of all oriented lines through the origin in three dimensional space. If you think about it you can identify them uniquely with the points on the sphere (the one they pass through "on the way out") and if you consider their "distance" from each other to be the differences between the angles of departure from the origin you will generate the standard topology on the sphere. Now consider unoriented lines. You can start with the sphere again, but then you identify points on opposite sides with each other because it doesn't matter what direction you're going. This is RP^2, 2-dimensional real projective space, which is a lot different from your plain old sphere and represents a minimal parametrization of unoriented lines.

  8. Windowlicker by lobiusmoop · · Score: 5, Interesting

    This reminds me of the Aphex Twin track Windowlicker, which, when viewed via a spectrogram, shows hidden images - Richard D. James' face, and a spiral. This explains why the track sounds so weird in places - the music is being warped to generate the images.

    --
    "I bless every day that I continue to live, for every day is pure profit."
  9. Musical DNA by dgreenbe · · Score: 4, Interesting

    Musical DNA Software is actually doing something useful with mathematical patterns generated from music. Check it out.

  10. Applied theory by Blighten · · Score: 4, Funny

    Finally there's a hard piece of work that demostrates the usefulness of String Theory.... oh wait.... it doesn't.

  11. Re:Well... by Yoozer · · Score: 4, Funny

    Quit channeling Stockhausen ;).

  12. Re:Interesting, though limited. by sticks_us · · Score: 5, Interesting

    The study of Music Theory is highly recommended (though I wouldn't recommend it for a career choice) for anyone of a technical nature who really wants to be challenged.

    Beyond the simple technicalities of measure-by-measure analysis (what notes combine to find what chord? what notes form a pattern to yield what scale?) the body of known music as a whole forms a massive network of associations and references in the form of quotes, parody, mimesis, etc...it's almost as if music comments about other music.

    This network, combined with various social and cultural studies, really provides a rich field of exploration (for example, the reason we concentrate on music by dead white europeans from 1700-1900 may include a cultural bias, not just technical).

    The professional, academic fields of Music Theory, History, and Ethnomusicology are only now beginning to broaden the discussion, having been stuck in the early 1900s (I've known professors of music who will say, without irony, that there's nothing worth discussing since ca. 1915).

    So, on your I-IV-V comment, it's true that there are about a zillion compositions that use this chord progression, so an interesting question would be "what makes each composition different in its use of this repetitive structure?"

    The answers are always interesting, and can include discussions of different genres, barely-perceptible rhythmic features borrowed from other cultures, sound textures, audio effects, and on and on.

    Fun times.

    --
    "Beware of bugs in the above code; I have only proved it correct, not tried it." -- Donald Knuth
  13. Sonny Bono owns you by tepples · · Score: 3, Insightful

    This network, combined with various social and cultural studies, really provides a rich field of exploration (for example, the reason we concentrate on music by dead white europeans from 1700-1900 may include a cultural bias, not just technical). "White" and "Europeans" might come from cultural bias, but the "dead" part comes from copyright, specifically the U.S. term extensions of 1976 and 1998. It's much more expensive for schools to provide copies of "Rhapsody in Blue" or any more recent work, so schools just pretend Gershwin's compositions never happened.
  14. Re:Here comes the land rush by radicalskeptic · · Score: 3, Informative

    You can't copyright chord progressions, only melodies. Most famously, there have been dozens of jazz standards written that are based on the chord progression of Gershwin's "I've Got Rhythm". In fact, there's even a name for that form: "'Rhythm Changes".

    --
    WARNING: If accidentally read, induce vomiting.
  15. ObligatoryJack Black quotation by Potor · · Score: 4, Funny

    I don't need no instructions to know how to ROCK!

  16. Re:Watched the .movs by Oktober+Sunset · · Score: 3, Insightful

    but would running an episode of american idol through it give goatse?
    If it did, It would be an improvement.
  17. First Article on Music Theory they ever published? by Vreejack · · Score: 4, Informative

    This is emphatically NOT the first paper on music theory they have ever run. A cursory search turned up several other recent papers. I'm too busy reading Dmitri Tymoczko's report on "The Geometry of Musical Chords" to write any more ---Science 7 July 2006:
    Vol. 313. no. 5783, pp. 72 - 74
    DOI: 10.1126/science.1126287

    --
    "Will future ages believe that such stupid bigotry ever existed!" -- Ivanhoe
  18. Multidimensions are unnecessary by Ralph+Spoilsport · · Score: 4, Interesting
    You don't need "higher dimensions" to do this at all. In fact, it's insanely simple, and is governed by numbers. Like Boards of Canada said, Music is Math.

    It works like this: you use an algorithm that puts together in a very orderly fashion every possible note combination. Think of this as Serialism gone buttfuck crazy. If your system has only one note, and only one duration, then it can be represented in binary: 1 = note, 0 = silence. You can arbitrarily limit the duration (set definition) in question. So, let's say it's 8 measures.

    So, every possible combination of 1 and zero becomes a number in this system, and so every melody can be identified.

    Now, just multiply pitches, give it a number, and you get melody - 1,6,21,4,55, etc. Then you establish a simple number as your base "speed" (say, 120) and you can calculate the fastest possible repetition of a sound before it buzzes into a sound itself (something over 20 beats per second, so let's say 64th notes) and you then establish that as your "Planck" note duration. You then establish the number of possible pitches (the MIDI 128 will do for now) and then it's on to harmony.

    Harmony (harmonies, triads, and chords, clusters, etc.) is simply melody stacked on top of itself. So, you then put some upper limit on the number of "voices" you wish to consider. An orchestra has 80+ voices, so let's make it a nice number like 100. So, you then take one melody.

    So, now we have to calculate all the possible (128) pitches and silences for 8 measures for one melody. That gives you a number. Then you calculate it for each voice in sequence, and that gives you another number. Keep calculating. You will end up with a VERY large number of numbers, but you will be able to calculate EVERY POSSIBLE melody, harmony, triad and chord, in EVERY POSSIBLE rhythm within the parameters of your system (which, at 64th notes at 120bpm with a range of 128 notes, is REALLY FREAKIN' HUGE).

    Except for primes, all numbers are the products of two smaller numbers greater than 1, so, one could then arrive at an equation of simple numbers arranged in additions and multiplications that would provide the given number to express a given piece of music. In fact, it would, in essence, express ALL music, as a given song would consist of a number expressing 8 measures, which is then followed by another number expressing 8 measures, etc. It's completely linear.

    So, the first 8 bars might be [(a+b+c)(df)+g] which is then followed by [h(ij)+(kl)] which describes the next 8 measures, etc.

    The computer would do the calculations themselves on demand. And this is where the EVIL FUN begins:

    What you do is with this system, ANY piece of notated music could be fed into the computer, and it would then "find" that music inside the system, and ALL SONGWRITERS would have to PAY royalties on the music the computer has generated.

    "Buh buh buh I'm an artist and I wrote this song. It goes Gm / Gm7 / A / D / G for eight bars and then..." Buh buh bullshit buddy: you song is located RIGHT HERE in my MASTER MUSIC PLAN. It's number consists of 10^42 digits and starts with "234895230498000345600045345" and ends with "3489000234502340523065023045604004506340" See? Right there.... Now PAY UP MOTHERFUCKER...

    "buh buh buh..."

    "ALL YOUR SONGS ARE BELONG TO ME!!!! now PAY UP!!!! I make the RIAA look like a bunch of GIRL SCOUTS!!! PAY UP!!! NOW!!!!"

    See? We don't need "multidimensional systems" to describe music - it can be done linearly. And it can make the guy who builds this damn thing filthy fucking rich.

    RS

    --
    Shoes for Industry. Shoes for the Dead.
  19. Pitch is Boring -- study rhythm by kov · · Score: 3, Insightful

    Music theory is miles deep in frequency analysis, throw this one on that slag heap. I do congratulate him on proving that pitch is boring though: since his chordal (i.e., pitch-based) analysis manages to lump vastly different musics together, ironically he's shown that the vast majority of what makes them different from each other must be something else.