Principal conductors have been Armand Marsick, Vladimir Golschmann, Jesús Arámbarri, José Limantour, Antoine de Babier, Rafael Frühbeck de Burgos, Alberto Bolet, Pedro Pirfano, Urbano Ruiz Laorden and Theo Alcántara.

It has also been conducted by Maurice Ravel, Jesús Guridi, Pablo Sorozábal, Krzysztof Penderecki, Carmelo Bernaola, Luis de Pablo, Ernesto and Cristóbal Halffter and other composers performing their own works.

The BOS was invited to perform at Mariinski Theatre in Saint Petersburg, Russia, for the 300th Anniversary of the city.

[2] In 1998 it represented the Basque Country at the World Expo in Lisbon, and in 1999 it took part in the inauguration of the Euskalduna Palace in Bilbao.

At the end of the nineties an agreement was reached with the multi-national company NAXOS to record 30 CDs, and the results of these are now appearing.