This first vocal-instrumental ensemble in Poland to perform old music was founded in 1957 by Stefan Sutkowski. Its aim was to popularize the newly discovered historical pieces of Polish music. In time, the ensemble and its repertoire expanded and its musicians and vocalists established Warsaw Chamber Opera. Since 1991, the ensemble has played period instruments, and its members have studied with the most prominent specialists in Europe. The ensemble has been run by the eminent harpsichord player W. Kłosiewicz; they participate in the annual Festival of Baroque Operas in Warsaw and in Mozart Festivals. The repertoire comprises all operas by Monteverdi (as well as other stage works) and other Baroque operas, e.g. by such composers as S. Landi (Il Sant`Alesio), J. Peri (Euridice), J.B. Lully (Alceste), A. Campa (Tancred), J. Blow (Venus and Adonis), H. Purcell (Dido and Aeneas). The ensemble also performs late Baroque operas (A. Scarlatti, G.F. Handel, G.T. Telemann, J.A. Hasse). Since 1999, its Old Instruments Ensemble has taken part in the Festival of Old Polish Operas in Krakowiacy i Górale (Cracovians and Highlanders) by W. Bogusławski and Stefani (also recorded on CD).