Assessing creativity in computer music ensembles: a computational approach

Abstract

Over the last decade Laptop Orchestras and Mobile Ensembles have proliferated. As a result, a large body of research has arisen on infrastructure, evaluation, design principles and compositional methodologies for Computer Music Ensembles (CME). However, little has been addressed and very little is known about the challenges and opportunities provided by CMEs for creativity in musical performance. Therefore, one of the most common issues CMEs have to deal with is the lack of a systematic approach to handle the implications of the performative paradigms they seek to explore, in terms of their creative constraints and affordances. This is the challenging goal this thesis addresses, and for attaining so it first seeks to find a common ground in the strategies developed for assessing creativity in different performative setups, for later proposing an informed pathway for performative engagement in CMEs. Our research combines an exploratory stage and an experimental stage. The exploratory stage was informed by out artistic praxis with our own CME, the Barcelona Laptop Orchestra. Through the study of the multi-user instruments developed over the past years, we identified the creative constraints and affordances provided by different performative paradigms. Informed by the findings provided by our artistic research, the experimental stage addressed the study of musical creativity through the performance analysis on specifically designed multi-user instruments. For such purpose we proposed a novel computational methodology to evaluate the creative content of a musical performance. Two experiments were conducted to incorporate our computational methodology into ecologically valid scenarios, aimed at a better understanding of the relationship between topologies of interdependence and creative outcome. For both experiments, we captured performance data from ensemble improvisations, from where the creativity metrics were then computed. As a preliminary step, we investigated the performative engagement and sharing of musical ideations in an ensemble scenario. In a further step, we computed the creativity attributes to comparatively evaluate performances under different scenarios. The findings provided quantitative evidence of the differences between musical creativity in individual, ensemble and interdependent scenarios. Additionally, the findings point out what strategies performers adopt to best keep their own musical voice in interdependence scenarios, and what novel creative behaviors may be promoted through new topologies of interdependence. Our findings shed light on the nature of performers’ creative behavior with interdependent multi-user instruments, and show that the introduced methodology can have applications in the broader context of analysis of creativity in musical performance.

Durant la darrera d`ecada les Laptop Orchestras i els Mobile Ensembles han proliferat arreu. Com a conseq¨u`encia d’aix`o, ha aparegut un volum considerable de recerca al voltant de la infraestructura, l’avaluaci´o, els principis de disseny i les metodologies composicionals per ensembles de computadors (CMEs). Tanmateix, poc coneixem dels reptes i oportunitats que els CMEs ens ofereixen respecte de la creativitat en la pr`actica musical. En conseq¨u`encia, un dels reptes que la majoria de CMEs han d’encarar ´es la manca d’una estrat`egia sistem` atica per preveure i abordar les implicacions dels paradigmes performatius a explorar, respecte de les seves limitacions i possibilitats creatives. Aquest ´es el repte que adrecem en aquesta tesi, i per assolir-lo primer tractem d’establir un denominador com´u en les estrat`egies desenvolupades per avaluar la creativitat en diversos entorns performatius, per despr´es proposar un itinerari que permeti assolir una adequada involucraci´o creativa en els CMEs. La nostra recerca ha combinat una fase explorat`oria i una d’experimental. La fase explorat`oria s’ha fonamentat en la praxi art´ıstica duta a terme en el nostre propi CME, la Barcelona Laptop Orchestra. A trav´es de l’estudi dels instruments multi-usuari desenvolupats durant els darrers anys, hem identificat les potencialitats i restriccions presents en diversos paradigmes performatius. Basats en els resultats de la nostra recerca art´ıstica, la fase experimental s’ha centrat en l’estudi de la creativitat musical a trav´es de l’an`alisi interpretatiu en instruments multiusuari desenvolupats a tal efecte. A tal fi, hem proposat una nova metodologia computacional per avaluar el contingut creatiu d’una execuci´o musical. Hem dut a terme dos experiments incorporant la nostra m`etrica en escenaris realistes, a fi de comprendre millor la relaci´o entre topologies d’interdepend`encia i resultat creatiu. Per ambd´os experiments, hem recollit informaci´o d’improvisacions en grup, d’on hem calculat les m`etriques de creativitat. Com a pas previ, hem investigat en grau d’involucraci´o i la compartici´o d’ideacions musicals en escenaris col lectius. Tot seguit, hem calculat els atributs de creativitat per comparar execucions musicals en diferents escenaris. Els resultats proporcionen una evid`encia quantitativa de la difer`encia entre la creativitat musical en escenaris d’execuci´o musical individual, en grup i interdependent. Addicionalment, ens il lustren quines estrat`egies adopten els m´usics per mantenir la seva pr`opia individualitat musical en escenaris d’interdepend`encia, i quins nous comportaments creatius podem promoure a trav´es de noves topologies d’interdepend`encia. Els resultats obtinguts aporten nova llum en la natura del comportament creatiu dels m´usics amb instruments multi-usuari interdependents, i mostren que la metodologia presentada pot tenir aplicacions en el context m´es ampli de l’an`alisi de la creativitat musical en l’execuci´o musical.