The Gulbenkian Choir was founded in 1964 by the Calouste Gulbenkian Foundation. Although the choir numbers about a hundred singers, it can also appear as a smaller vocal ensemble, according to the nature of the works performed. Thus the Gulbenkian Choir may appear as an a cappella ensemble, performing sixteenth- to eighteenth-century Portuguese polyphony, or join the Gulbenkian Orchestra or other orchestras to perform the Classical and Romantic mainstream choral-symphonic literature. It also performs twentieth-century music, and often gives the premières of many contemporary works by Portuguese and international composers. It has been frequently invited to collaborate with major international orchestras, working under distinguished conductors. Besides its regular season in Lisbon and its national tours, the Gulbenkian Choir has undertaken concert tours throughout the world. The choir has collaborated with important music festivals around the world, and has recorded extensively for Philips, Archiv-Deutsche Grammophon, Erato, Cascavelle, Musifrance, FNAC-Music, performing a wide-ranging repertoire, with several of these recordings receiving international awards. Michel Corboz has been the chief conductor of the Gulbenkian Choir since 1969, with Fernando Eldoro and Jorge Matta as associate and assistant conductors respectively.