According to the Guiness Book of Records, "Happy Birthday To You!" is one of the world's most frequently sung songs. Words and music are by two sisters from Louisville, Kentucky: Patty Hill, a pioneer kindergarten teacher and Mildred Hill, a musician. They combined their talents to produce this song, suitable for children's voices as well as all others. Patty drew 3,000 teachers to a workshop she gave at the 1893 Chicago Worlds Fair. Shortly afterwards she was invited to establish the Department of Nursery School, Kindergarten, and First-Grade Education at Columbia University. She was the first woman to receive and honorary doctorate from Columbia.