For over a thousand years, the spring season has been greeted through Vesnianky, a beautiful ritual integrating music, poetry, and round dances. In Summer, the festival of Kupalo is usually celebrated with the Kupalo folk dance and songs. Women weave wreaths of flowers and ferns that are for luck, strength, and prosperity. Elders and young people alike sing songs in the hopes of a successful growing season. During the early 15th century, the Hopak dance, which emerged as a kind of martial art, gradually found a new role as a social dance. Complex acrobatic movements include squats, leaps, and stretches on the ground or in the air. Today the Hopak is the national dance of Ukraine. Vasyl Verkhovynets is known as a champion of Ukrainian folk dance. In 1919 he published his landmark book “Theory of Ukrainian Folk Dance” based on his research, recording the choreography of Ukrainian folk dance for the first time. The mid-August International Ukrainian Dance and Culture Festival (IUDCF) is a four-day event that provides a prominent stage for dancers and performers from around the world to demonstrate their talents in Ukrainian folk dance. Performance of Ukrainian folk songs takes many forms, such as authentic folk singing, singing in ensembles, folkloric ensembles, art singing, choral art singing, and accompanied singing. Nina Matviyenko is one of the most popular traditional Ukrainian folk singers of the modern era. Honored as a People's Artist of Ukraine, and recipient of the highest state prize, the Shevchenko National Prize, Nina frequently performs on TV, in films, and on radio. The Ukrainian National Choir, the Ukrainian Chorus Dumka, and the Boyan Ensemble are famous choral singing groups during the 20th century. Substantial efforts have been made to preserve Ukrainian folk songs. For instance, the Hungarian ethnographer Miklós Both founded the Polyphony Project that collects folk music and songs in Ukraine. “Moon in the Sky” is one of the most beloved Ukrainian folk songs, and is considered a folk masterpiece.