The Casals Quartet is a Spanish string quartet based at l'Auditori in Barcelona, where all four members reside and teach at the Escola Superior de Musica de Catalunya.
From Wikipedia (https://en.wikipedia.org/wiki/Cuarteto_Casals) under Creative Commons Attribution CC-BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/legalcode)