Expressive non-verbal interaction in a string quartet.
D. Glowinski1, G. Gnecco2 , A. Camurri3, S. Piana3 1NEAD, University of Geneve, Geneve, Switzerland
[email protected]
2IMT
Italy
– Institute for Advanced Studies - Lucca,
[email protected]
3DIBRIS,
University of Genova, Italy
{antonio.camurri, stefano.piana}@unige.it
String quartet scenario
Distinguishing levels of expressivity of group performance based on geometric features. Two kinds of group performance were considered: In the first setting (condition A), the four musicians were instructed to play 5 times a music piece at best in a concert-like situation. In the second setting (condition B), the 1st violinist of the string quartet devised alternative interpretations of the same piece, which contradict the usual interpretation.
Expressive group performance
Method: four features related to head movement and direction that may help gaining insight on the expressivity and also cohesion of the performance Expressivity and cohesion evaluated by the musicians themselves through post-performance ratings on a 7-items Likert scale, answering questions like “how emotionally engaging was your performance?” “how did you manage to coordinate with the other musicians?”
Post-performance ratings
t(38)= 12.13, p < .001
Group feature n°1
Convergence of head directions toward the ear
significant difference for F1,2
U= 0, p = .008
Concert-like condition
SQ ear played a central role to coordinate musicians and achieve a cohesive performance in both performing conditions A and B
Group feature n°2
Joint movement dynamics of the heads toward the ear
U= 25, p = .008 Confirm central role of SQ ear
Group feature n°3
Convergence of a subset of 3 head directions toward the remaining musician
Significant decrease of distance between 1st violinist and his associated point of partial convergence (PoPC1 ) in cond. B => 2nd violinist, violist and cellist’s heads are converging toward him. Perturbed condition
Group feature n°4
Focus of attention (FoA) of single musician
Distribution of the focus of attention − player 1 − Condition A 26% < 1% 11%
Quantifying how much 2nd violinist, violist and cellist are focusing on 1st violinist in condition A and B
63%
0 2 3 4
Distribution of the focus of attention − player 1 − Condition B 27% < 1% 25%
48%
0 2 3 4
Distribution of the focus of attention − player 2 − Condition A 5% 6% 0 1 4
Distribution of the focus of attention − player 2 − Condition B < 1% 11% 0 1 4
89% Distribution of the focus of attention − player 3 − Condition A < 1% 2% 0 1 2 97%
89% Distribution of the focus of attention − player 3 − Condition B 1% < 1% 26% 0 1 2 72% 4
Distribution of the focus of attention − player 4 − Condition A 1% 16% 18% 0 1 2 3 65%
Distribution of the focus of attention − player 4 − Condition B 9%< 1% 8% 0 1 2 3 82%
For 1st violinist, significant difference between the two conditions U= 8282, p < .001
Discussion and future work Selected four features related to head movement and direction help gaining insight on the expressivity and cohesion of the performance attention to other performers’ heads help to better predict their upcoming action Future work will include: computation of the features at a local scale application of our methodology to other SQs and other settings use of more sophisticated classification methods (e.g., SVMs) to highlight the discriminative power of the features
