Tuesday, June 26, 2012

Herkent u deze melodie? [Dutch]

Je zit in je auto en draait wat aan de knop van de radio. Je hoort al snel of bepaalde muziek je bevalt of niet. Je herkent een stem, een liedje of zelfs de uitvoering ervan. Iedereen doet het, iedereen kan het. En vaak ook nog eens razendsnel: sneller dan een noot gemiddeld klinkt.

Als u gevraagd zou worden om naar een reeks muziekfragmenten van 0,2 seconde te luisteren, zal blijken dat u met gemak aan kan geven welk fragment klassiek, jazz, R&B of pop is (zie luistertest). Een snippertje geluid geeft ons toegang tot de herinnering aan eerder gehoorde muziek, ook al hebben we deze serie noten nog nooit eerder gehoord. Die herinnering kan heel specifiek zijn: aan een liedje van Björk, bijvoorbeeld. Maar ze kan ook heel algemeen zijn: we herkennen een bepaald genre: klassiek, country, jazz. De nuances in klankkleur, karakteristiek voor een liedje of een heel genre, zitten kennelijk op een abstracte manier in ons geheugen opgeslagen. Daarom is de draaiknop (of tiptoets) van de autoradio zo’n succesvolle interface geworden…

Vandaag verschenen er verschillende items in de media n.a.v. van een stukje in Volkskrant over de oorwurm en de hype rond Song Pop, een app die gebruik maakt van het hierboven beschreven muzikale talent dat we allemaal delen: het razendsnel herkennen van muziek.

ResearchBlogging.org Gjerdingen, Robert O., & Perrott, D. (2008). Scanning the Dial: The Rapid Recognition of Music Genres Journal of New Music Research, 37 (2), 93-100 DOI: 10.1080/09298210802479268

Thursday, June 21, 2012

Can artificial music evolve in a Darwinian way?

Natural selection expresses the idea that organisms (i.e. their genes) vary and that variability has consequences. Some variants are unfit and go extinct, others adapt and do well. This process, repeated over millions of years, has given us the variety of life on earth.

Many authors have played with the idea how to combine these insights from evolutionary biology to changes in culture, the notion of ‘memes’ being one of them. Richard Dawkins proposed that human culture is composed of a multitude of particulate units, memes, which are analogous to the genes of biological transmission. These cultural replicators are transmitted by imitation between members of a community and are subject to mutational-evolutionary pressures over time.

This week an interesting study appeared in PNAS (early edition) showing that a simple Darwinian process can produce music. Inspired by cultural transmission theory, the study suggests that the evolution of music can be viewed and analyzed in terms of selection-variation processes, and, as such, may shed light on the evolution of real musical cultures.

The experiment described in the paper works as follows: An algorithm maintains a population of tree-like digital genomes, each of which encodes a computer program. Each genome-program specifies note placement, instrumentation, and performance parameters (with tempo, meter, and tuning system fixed for all loops). Loops periodically replicate to produce new loops. The selective pressure on the music that is generated comes from a population of consumers who listen to samples of the loops via a Web interface (DarwinTunes) and rate them for their appeal. These ratings are then the basis of a fitness function that determines which loops in a given generation will be allowed to mate and reproduce.

ResearchBlogging.org Robert M. MacCallum, Matthias Mauch, Austin Burta, & Armand M. Leroi (2012). Evolution of music by public choice. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1203182109

(See also earlier blog entry).

Synesthesia as an alternative explanation of a chimps' exceptional memory?

Have a look at this video. (N.B. it is played back at normal speed)

After the numbers 1 through 9 make a split-second appearance on a computer screen, the chimp, Ayumu, gets to work. His index finger moves quickly across the screen, tapping white squares where the numbers had appeared, in order. Ayumu’s talent caused a quite a stir when researchers first reported it (Matsuzawa, 2009).

In an upcoming Trends in Cognitive Sciences essay, Nicholas Humphrey floats a different explanation for Ayumu’s superlative performance: Ayumu might have a curious brain condition that allows him to see numbers in colors. A simple experiment could reveal whether Ayumu is synesthetic: Changing the white square to colored squares would throw him off if he was relying on colors to order the numbers. According to ScienceNews Matsuzawa, who declined to comment directly on Humphrey’s theory, has no plans to test this.

ResearchBlogging.org Nicholas Humphrey (2012). ‘This chimp will kick your ass at memory games – but how the hell does he do it?’ Trends in Cognitive Science DOI: 10.1016/j.tics.2012.05.002

ResearchBlogging.org Tetsuro Matsuzawa (2009). Symbolic representation of number in chimpanzees Current Opinion in Neurobiology, 19 (1), 92-98 DOI: 10.1016/j.conb.2009.04.007

Wednesday, June 20, 2012

Why does a well-tuned modern piano not sound out-of tune?

Karlheinz Stockhausen is listening.
"Neue Musik ist anstrengend", wrote Die Zeit some time ago: "Der seit Pythagoras’ Zeiten unternommene Versuch, angenehme musikalische Klänge auf ganzzahlige Frequenzverhältnisse der Töne zurückzuführen, ist schon mathematisch zum Scheitern verurteilt. Außereuropäische Kulturen beweisen schließlich, dass unsere westliche Tonskala genauso wenig naturgegeben ist wie eine auf Dur und Moll beruhende Harmonik: Die indonesische Gamelan-Musik und Indiens Raga-Skalen klingen für europäische Ohren schräg."

The definition of music as “sound” wrongly suggests that music, like all natural phenomena, adheres to the laws of nature. In this case, the laws would be the acoustical patterns of sound such as the (harmonic) relationships in the structure of the dominant tones, which determine the timbre. This is an idea that has preoccupied primarily the mathematically oriented music scientists, from Pythagoras to Hermann von Helmholtz.

The first, and oldest, of these scientists, Pythagoras, observed, for example, that “beautiful” consonant intervals consist of simple frequency relationships (such as 2:3 or 3:4). Several centuries later, Galileo Galilei wrote that complex frequency relationships only “tormented” the eardrum.

But, for all their wisdom, Pythagoras, Galilei, and like-minded thinkers got it wrong. In music, the “beautiful,” so-called “whole-number” frequency relationships rarely occur—in fact, only when a composer dictates them. The composer often even has to have special instruments built to achieve them, as American composer Harry Partch did in the twentieth century.

Contemporary pianos are tuned in such a way that the sounds produced only approximate all those beautiful “natural” relationships. The tones of the instrument do not have simple whole number ratios, as in 2:3 or 3:4. Instead, they are tuned so that every octave is divided into twelve equal parts (a compromise to facilitate changes of key). The tones exist, therefore, not as whole number ratios of each other, but as multiples of 12√2 (1:1.05946).

According to Galilei, each and every one of these frequency relationships are “a torment” to the ear. But modern listeners experience them very differently. They don’t particularly care how an instrument is tuned, otherwise many a concertgoer would walk out of a piano recital because the piano sounded out of tune. It seems that our ears adapt quickly to “dissonant” frequencies. One might even conclude that whether a piano is “in tune” or “out of tune” is entirely irrelevant to our appreciation of music. [fragment from Honing, 2011.]

ResearchBlogging.orgJulia Kursell (2011). Kräftespiel. Zur Dissymmetrie von Schall und Wahrnehmung. Zeitschrift für Medienwissenschaft, 2 (1), 24-40 DOI: 10.4472_zfmw.2010.0003

ResearchBlogging.orgHoning, H. (2012). Een vertelling. In S. van der Maas, C. Hulshof, & P. Oldenhave (Eds.), Liber Plurum Vocum voor Rokus de Groot (pp. 150-154). Amsterdam: Universiteit van Amsterdam (ISBN 978-90-818488-0-0).

ResearchBlogging.orgWhalley, Ian. (2006). William A. Sethares: Tuning, Timbre, Spectrum, Scale (Second Edition). Computer Music Journal, 30 (2) DOI: 10.1162/comj.2006.30.2.92

Thursday, June 14, 2012

Interested in an Associate Professorship at the UvA?

To strengthen its Research Priority Area Brain & Cognition, the Faculty of Humanities invites applications for an Associate Professor in Cognitive Modelling.

The candidate will bring a relevant and innovative research agenda in cognitive modelling that strengthens the contributions from the ILLC to the research priority area Brain & Cognition. In addition to the Brain & Cognition subthemes, possible topics include, but are not restricted to, the cognitive modelling of music, language, evolution of cognition, and/or cultural transmission.

For more information on how to apply see here.

Deadline for applications: 1 August 2012.

Friday, June 08, 2012

Interested in doing a PhD at the UvA?

To strengthen its Research Priority Area Brain & Cognition, the Faculty of Humanities invites applications for a PhD candidate in Cognitive Modelling, starting on 1st September 2012.

Applications are now invited from excellent candidates wishing to conduct research in the field of cognitive science and cognitive modelling in the context of the Brain & Cognition Research Priority Area. In addition to the Brain & Cognition subthemes, possible topics include, but are not restricted to, the cognitive modelling of music, language, evolution of cognition, and/or cultural transmission.

The PhD candidate will be part of the Institute for Logic, Language and Computation (ILLC).

See for more information on how to apply here.

Deadline for applications: 4 July 2012.

Wednesday, June 06, 2012

Weet je wat je hoort? [Dutch]

Deze week verscheen er een nieuwe versie van het boek Iedereen is muzikaal. Deze editie is uitgebreid met een nawoord, een appendix en directe QR-verwijzingen naar luistervoorbeelden, korte testjes en demonstraties. Diverse media besteedde er aandacht aan. Hieronder een interview bij 3fm.

Wordt popmuziek steeds treuriger? [Dutch]

Socioloog Christian von Scheve (Freie Universität Berlin) en muziek-psycholoog Glenn Schellenberg (University of Toronto) analyseerden zo’n duizend liedjes die tussen 1965 en 2009 in de Amerikaanse hitlijsten stonden. Daarbij vergeleken ze onder meer toonsoorten en tempo’s.

De onderzoekers concludeerden dat er nu meer liedjes in de hitlijsten verschijnen die in mineur worden geschreven dan in de jaren zestig. Van mineurnummers is bekend dat ze een gevoel van verdriet opwekken. Derhalve stellen de onderzoekers dat nummers in de hitlijsten steeds treuriger worden (bron: Nu.nl).

Maar hoe ‘mineur’ klikken popsongs in mineur eigenlijk? Denk bijvoorbeeld aan Everybody van de Backstreet Boys of Love Game van Lady Gaga…

[Item op Radio 2]

ResearchBlogging.org Schellenberg, E., & von Scheve, C. (2012). Emotional Cues in American Popular Music: Five Decades of the Top 40. Psychology of Aesthetics, Creativity, and the Arts DOI: 10.1037/a0028024