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date Mon, 12 Mar 2012 20:00:25 +0000
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462 \section{Information Dynamics in Analysis} 462 \section{Information Dynamics in Analysis}
463 463
464 \subsection{Musicological Analysis} 464 \subsection{Musicological Analysis}
465 refer to the work with the analysis of minimalist pieces 465 refer to the work with the analysis of minimalist pieces
466 466
467 \subsection{Content analysis/Sound Categorisation}. Using Information Dynamics it is possible to segment music. From there we can then use this to search large data sets. Determine musical structure for the purpose of playlist navigation and search. 467 \subsection{Content analysis/Sound Categorisation}.
468 Using Information Dynamics it is possible to segment music. From there we
469 can then use this to search large data sets. Determine musical structure for
470 the purpose of playlist navigation and search.
468 \emph{Peter} 471 \emph{Peter}
469 472
470 \subsection{Beat Tracking} 473 \subsection{Beat Tracking}
471 \emph{Andrew} 474 \emph{Andrew}
472 475
473 476
474 \section{Information Dynamics as Design Tool} 477 \section{Information Dynamics as Design Tool}
475 478
476 In addition to applying information dynamics to analysis, it is also possible use this approach in design, such as the composition of musical materials. 479 In addition to applying information dynamics to analysis, it is also possible
477 By providing a framework for linking information theoretic measures to the control of generative processes, it becomes possible to steer the output of these processes to match a criteria defined by these measures. 480 use this approach in design, such as the composition of musical materials. By
478 For instance outputs of a stochastic musical process could be filtered to match constraints defined by a set of information theoretic measures. 481 providing a framework for linking information theoretic measures to the control
479 482 of generative processes, it becomes possible to steer the output of these processes
480 The use of stochastic processes for the generation of musical material has been widespread for decades -- Iannis Xenakis applied probabilistic mathematical models to the creation of musical materials, including to the formulation of a theory of Markovian Stochastic Music. 483 to match a criteria defined by these measures. For instance outputs of a
481 However we can use information dynamics measures to explore and interface with such processes at the high and abstract level of expectation, randomness and predictability. 484 stochastic musical process could be filtered to match constraints defined by a
482 The Melody Triangle is such a system. 485 set of information theoretic measures.
483 486
484 \subsection{The Melody Triangle} The Melody Triangle is an exploratory interface for the discovery of melodic content, where the input -- positions within a triangle -- directly map to information theoretic measures associated with the output. 487 The use of stochastic processes for the generation of musical material has been
485 The measures are the entropy rate, redundancy and predictive information rate of the random process used to generate the sequence of notes. 488 widespread for decades -- Iannis Xenakis applied probabilistic mathematical
486 These are all related to the predictability of the the sequence and as such address the notions of expectation and surprise in the perception of music.\emph{self-plagiarised} 489 models to the creation of musical materials, including to the formulation of a
490 theory of Markovian Stochastic Music. However we can use information dynamics
491 measures to explore and interface with such processes at the high and abstract
492 level of expectation, randomness and predictability. The Melody Triangle is
493 such a system.
494
495 \subsection{The Melody Triangle}
496 The Melody Triangle is an exploratory interface for the discovery of melodic
497 content, where the input -- positions within a triangle -- directly map to
498 information theoretic measures associated with the output.
499 The measures are the entropy rate, redundancy and predictive information rate
500 of the random process used to generate the sequence of notes.
501 These are all related to the predictability of the the sequence and as such
502 address the notions of expectation and surprise in the perception of
503 music.\emph{self-plagiarised}
487 504
488 Before the Melody Triangle can used, it has to be ÔpopulatedÕ with possible parameter values for the melody generators. 505 Before the Melody Triangle can used, it has to be `populated' with possible
489 These are then plotted in a 3d statistical space of redundancy, entropy rate and predictive information rate. 506 parameter values for the melody generators. These are then plotted in a 3d
490 In our case we generated thousands of transition matrixes, representing first-order Markov chains, by a random sampling method. In figure \ref{InfoDynEngine} we see a representation of how these matrixes are distributed in the 3d statistical space; each one of these points corresponds to a transition matrix.\emph{self-plagiarised} 507 statistical space of redundancy, entropy rate and predictive information rate.
508 In our case we generated thousands of transition matrixes, representing first-order
509 Markov chains, by a random sampling method. In figure \ref{InfoDynEngine} we see
510 a representation of how these matrixes are distributed in the 3d statistical
511 space; each one of these points corresponds to a transition
512 matrix.\emph{self-plagiarised}
491 513
492 \begin{figure} 514 \begin{figure}
493 \centering 515 \centering
494 \includegraphics[width=\linewidth]{figs/mtriscat} 516 \includegraphics[width=\linewidth]{figs/mtriscat}
495 \caption{The population of transition matrices distributed along three axes of 517 \caption{The population of transition matrices distributed along three axes of
502 not visible in this plot, it is largely hollow in the middle. 524 not visible in this plot, it is largely hollow in the middle.
503 \label{InfoDynEngine}} 525 \label{InfoDynEngine}}
504 \end{figure} 526 \end{figure}
505 527
506 528
507 When we look at the distribution of transition matrixes plotted in this space, we see that it forms an arch shape that is fairly thin. 529 When we look at the distribution of transition matrixes plotted in this space,
508 It thus becomes a reasonable approximation to pretend that it is just a sheet in two dimensions; and so we stretch out this curved arc into a flat triangle. 530 we see that it forms an arch shape that is fairly thin. It thus becomes a
509 It is this triangular sheet that is our ÔMelody TriangleÕ and forms the interface by which the system is controlled. \emph{self-plagiarised} 531 reasonable approximation to pretend that it is just a sheet in two dimensions;
510 532 and so we stretch out this curved arc into a flat triangle. It is this triangular
511 When the Melody Triangle is used, regardless of whether it is as a screen based system, or as an interactive installation, it involves a mapping to this statistical space. 533 sheet that is our `Melody Triangle' and forms the interface by which the system
512 When the user, through the interface, selects a position within the triangle, the corresponding transition matrix is returned. 534 is controlled. \emph{self-plagiarised}
513 Figure \ref{TheTriangle} shows how the triangle maps to different measures of redundancy, entropy rate and predictive information rate.\emph{self-plagiarised} 535
536 When the Melody Triangle is used, regardless of whether it is as a screen based
537 system, or as an interactive installation, it involves a mapping to this statistical
538 space. When the user, through the interface, selects a position within the
539 triangle, the corresponding transition matrix is returned. Figure \ref{TheTriangle}
540 shows how the triangle maps to different measures of redundancy, entropy rate
541 and predictive information rate.\emph{self-plagiarised}
514 \begin{figure} 542 \begin{figure}
515 \centering 543 \centering
516 \includegraphics[width=\linewidth]{figs/TheTriangle.pdf} 544 \includegraphics[width=\linewidth]{figs/TheTriangle.pdf}
517 \caption{The Melody Triangle\label{TheTriangle}} 545 \caption{The Melody Triangle\label{TheTriangle}}
518 \end{figure} 546 \end{figure}
519 Each corner corresponds to three different extremes of predictability and unpredictability, which could be loosely characterised as ÔperiodicityÕ, ÔnoiseÕ and ÔrepetitionÕ. 547 Each corner corresponds to three different extremes of predictability and
520 Melodies from the ÔnoiseÕ corner have no discernible pattern; they have high entropy rate, low predictive information rate and low redundancy. 548 unpredictability, which could be loosely characterised as `periodicity', `noise'
521 These melodies are essentially totally random. 549 and `repetition'. Melodies from the `noise' corner have no discernible pattern;
522 A melody along the ÔperiodicityÕ to ÔrepetitionÕ edge are all deterministic loops that get shorter as we approach the ÔrepetitionÕ corner, until it becomes just one repeating note. 550 they have high entropy rate, low predictive information rate and low redundancy.
523 It is the areas in between the extremes that provide the more ÔinterestingÕ melodies. 551 These melodies are essentially totally random. A melody along the `periodicity'
524 That is, those that have some level of unpredictability, but are not completely ran- dom. Or, conversely, that are predictable, but not entirely so. 552 to `repetition' edge are all deterministic loops that get shorter as we approach
525 This triangular space allows for an intuitive explorationof expectation and surprise in temporal sequences based on a simple model of how one might guess the next event given the previous one.\emph{self-plagiarised} 553 the `repetition' corner, until it becomes just one repeating note. It is the
526 554 areas in between the extremes that provide the more `interesting' melodies. That
527 555 is, those that have some level of unpredictability, but are not completely ran-
528 556 dom. Or, conversely, that are predictable, but not entirely so. This triangular
529 Any number of interfaces could be developed for the Melody Triangle. 557 space allows for an intuitive explorationof expectation and surprise in temporal
530 We have developed two; a standard screen based interface where a user moves tokens with a mouse in and around a triangle on screen, and a multi-user interactive installation where a Kinect camera tracks individuals in a space and maps their positions in the space to the triangle. 558 sequences based on a simple model of how one might guess the next event given
531 Each visitor would generate a melody, and could collaborate with their co-visitors to generate musical textures -- a playful yet informative way to explore expectation and surprise in music. 559 the previous one.\emph{self-plagiarised}
532 560
533 As a screen based interface the Melody Triangle can serve as composition tool. 561
534 A triangle is drawn on the screen, screen space thus mapped to the statistical space of the Melody Triangle. 562
535 A number of round tokens, each representing a melody can be dragged in and around the triangle. 563 Any number of interfaces could be developed for the Melody Triangle. We have
536 When a token is dragged into the triangle, the system will start generating the sequence of notes with statistical properties that correspond to its position in the triangle.\emph{self-plagiarised} 564 developed two; a standard screen based interface where a user moves tokens with
537 565 a mouse in and around a triangle on screen, and a multi-user interactive
538 In this mode, the Melody Triangle can be used as a kind of composition assistant for the generation of interesting musical textures and melodies. 566 installation where a Kinect camera tracks individuals in a space and maps their
539 However unlike other computer aided composition tools or programming environments, here the composer engages with music on the high and abstract level of expectation, randomness and predictability.\emph{self-plagiarised} 567 positions in the space to the triangle.
540 568 Each visitor would generate a melody, and could collaborate with their co-visitors
569 to generate musical textures -- a playful yet informative way to explore
570 expectation and surprise in music.
571
572 As a screen based interface the Melody Triangle can serve as composition tool.
573 A triangle is drawn on the screen, screen space thus mapped to the statistical
574 space of the Melody Triangle.
575 A number of round tokens, each representing a melody can be dragged in and
576 around the triangle. When a token is dragged into the triangle, the system
577 will start generating the sequence of notes with statistical properties that
578 correspond to its position in the triangle.\emph{self-plagiarised}
579
580 In this mode, the Melody Triangle can be used as a kind of composition assistant
581 for the generation of interesting musical textures and melodies. However unlike
582 other computer aided composition tools or programming environments, here the
583 composer engages with music on the high and abstract level of expectation,
584 randomness and predictability.\emph{self-plagiarised}
585
541 586
542 Additionally the Melody Triangle serves as an effective tool for experimental investigations into musical preference and their relationship to the information dynamics models. 587 Additionally the Melody Triangle serves as an effective tool for experimental investigations into musical preference and their relationship to the information dynamics models.
543 588
544 %As the Melody Triangle essentially operates on a stream of symbols, it it is possible to apply the melody triangle to the design of non-sonic content. 589 %As the Melody Triangle essentially operates on a stream of symbols, it it is possible to apply the melody triangle to the design of non-sonic content.
545 590
546 \section{Musical Preference and Information Dynamics} 591 \section{Musical Preference and Information Dynamics}
547 We carried out a preliminary study that sought to identify any correlation between aesthetic preference and the information theoretical measures of the Melody Triangle. 592 We carried out a preliminary study that sought to identify any correlation between
548 In this study participants were asked to use the screen based interface but it was simplified so that all they could do was move tokens around. 593 aesthetic preference and the information theoretical measures of the Melody
549 To help discount visual biases, the axes of the triangle would be randomly rearranged for each participant.\emph{self-plagiarised} 594 Triangle. In this study participants were asked to use the screen based interface
550 595 but it was simplified so that all they could do was move tokens around. To help
551 The study was divided in to two parts, the first investigated musical preference with respect to single melodies at different tempos. 596 discount visual biases, the axes of the triangle would be randomly rearranged
552 In the second part of the study, a back- ground melody is playing and the participants are asked to find a second melody that Õworks wellÕ with the background melody. 597 for each participant.\emph{self-plagiarised}
553 For each participant this was done four times, each with a different background melody from four different areas of the Melody Triangle. 598
554 For all parts of the study the participants were asked to ÔmarkÕ, by pressing the space bar, whenever they liked what they were hearing.\emph{self-plagiarised} 599 The study was divided in to two parts, the first investigated musical preference
600 with respect to single melodies at different tempos. In the second part of the
601 study, a background melody is playing and the participants are asked to continue
602 playing with the system under the implicit assumption that they will try to find
603 a second melody that works well with the background melody. For each participant
604 this was done four times, each with a different background melody from four
605 different areas of the Melody Triangle. For all parts of the study the participants
606 were asked to signal, by pressing the space bar, whenever they liked what they
607 were hearing.\emph{self-plagiarised}
555 608
556 \emph{todo - results} 609 \emph{todo - results}
557 610
558 \section{Information Dynamics as Evaluative Feedback Mechanism} 611 \section{Information Dynamics as Evaluative Feedback Mechanism}
559 612
560 \emph{todo - code the info dyn evaluator :) } 613 \emph{todo - code the info dyn evaluator :) }
561 614
562 It is possible to use information dynamics measures to develop a kind of `critic' that would evaluate a stream of symbols. 615 It is possible to use information dynamics measures to develop a kind of `critic'
563 For instance we could develop a system to notify us if a stream of symbols is too boring, either because they are too repetitive or too chaotic. 616 that would evaluate a stream of symbols. For instance we could develop a system
564 This could be used to evaluate both pre-composed streams of symbols, or could even be used to provide real-time feedback in an improvisatory setup. 617 to notify us if a stream of symbols is too boring, either because they are too
565 618 repetitive or too chaotic. This could be used to evaluate both pre-composed
566 \emph{comparable system} Gordon Pask's Musicolor (1953) applied a similar notion of boredom in its design. 619 streams of symbols, or could even be used to provide real-time feedback in an
567 The Musicolour would react to audio input through a microphone by flashing coloured lights. 620 improvisatory setup.
568 Rather than a direct mapping of sound to light, Pask designed the device to be a partner to a performing musician. 621
569 It would adapt its lighting pattern based on the rhythms and frequencies it would hear, quickly `learning' to flash in time with the music. 622 \emph{comparable system} Gordon Pask's Musicolor (1953) applied a similar notion
570 However Pask endowed the device with the ability to `be bored'; if the rhythmic and frequency content of the input remained the same for too long it would listen for other rhythms and frequencies, only lighting when it heard these. 623 of boredom in its design. The Musicolour would react to audio input through a
571 As the Musicolour would `get bored', the musician would have to change and vary their playing, eliciting new and unexpected outputs in trying to keep the Musicolour interested. 624 microphone by flashing coloured lights. Rather than a direct mapping of sound
572 625 to light, Pask designed the device to be a partner to a performing musician. It
573 In a similar vain, our \emph{Information Dynamics Critic}(name?) allows for an evaluative measure of an input stream, however containing a more sophisticated notion of boredom that \dots 626 would adapt its lighting pattern based on the rhythms and frequencies it would
574 627 hear, quickly `learning' to flash in time with the music. However Pask endowed
628 the device with the ability to `be bored'; if the rhythmic and frequency content
629 of the input remained the same for too long it would listen for other rhythms
630 and frequencies, only lighting when it heard these. As the Musicolour would
631 `get bored', the musician would have to change and vary their playing, eliciting
632 new and unexpected outputs in trying to keep the Musicolour interested.
633
634 In a similar vein, our \emph{Information Dynamics Critic}(name?) allows for an
635 evaluative measure of an input stream, however containing a more sophisticated
636 notion of boredom that \dots
637
575 638
576 639
577 640
578 \section{Conclusion} 641 \section{Conclusion}
579 642