The ensemble OPERA APERTA was established in 1996 from the initiative of some players of the ensemble for contemporary music VENI ensemble as chamber orchestra for the music of classicistic-romantic tradition and 20th century. Its perspective instrumentation presupposes the appearance of a string quartet, piano, flute and clarinet. This definition opens up space and variability for realization of the plan of the ensemble: to form individual programs by differently defined parallel or vice versa counter-positions that create a dramaturgical bond of performed compositions. The realization of this idea is a long-term project, which aims to grasp and understand the European musical heritage from the perspective of the end of the 20th century.