In a musical first, all Mozart\'s theatrical works will get an airing by the Warsaw chamber orchestra at the 21st Mozart Festival which gets underway on Wednesday, the festival director said. The festival will thus be \"a unique performance\" Stefan Sutkowski enthused Monday. \"No other opera house in the world has played all Mozart\'s stage works in a row,\" he told reporters as he unveiled this year\'s festival programme. The Mozart marathon will take place in a pocket opera house, with just 159 seats, guaranteeing intimate performances. \"We are probably the smallest opera house in the world,\" said Sutkowski. The festival will get underway with a rendering of \"The Magic Flute\" followed by a kind of best of Mozart -- \"Don Giovanni,\" \"The Marriage of Figaro,\" \"Cosi Fan Tutte\" and \"The Abduction from the Seraglio.\" Lesser-known Mozart works, including \"Ascania in Alba,\" and the Opera buffa, or comic operas, \"The Goose of Cairo\" and \"The Deluded Bridegroom\", will also be featured. In order to perform another rarity, the pantomime ballet \"Les Petits Riens,\" new arrangements were produced for one part of the score where only simple notation exists, the festival director said. \"We have used all the Mozart we could,\" Sutkowski stressed. Besides the 22 Mozart stage works, the festival, which will run until July 26, will also include a number of chamber concerts, included the celebrated Requiem and the \"Mass in C Minor\". enter- fes