Croatian traditional patriotic songs—some of them banned—experienced a surge of popularity. The most popular and controversial singer of such songs at the time was Vice Vukov. "Lijepa naša domovino" returned to formal use as a patriotic song when a plaque was placed in the Zagreb Cathedral commemorating nobility involved in the 17th-century Magnate conspiracy. The opera "Nikola Šubić Zrinski", retelling the 16th-century Siege of Szigetvár, was regularly sold out whenever it played in the Croatian National Theatre in Zagreb. Oton Iveković's paintings, depicting events from the national history, became very popular. The historical chequy arms of Croatia became a popular symbol sewn by youths on jackets and berets or applied on stickers to car windshields. In 1969, it was incorporated in the crest of Dinamo Zagreb football club. While the Yugoslav flag was still flown, it was always paired with the Croatian one. The latter were also used on their own and outnumbered the Yugoslav flag by ten to one.