American pop is pop music in the United States. American folk singer Pete Seeger defined pop music as "professional music which draws upon both folk music and fine arts music". An early genre of American pop music was the swing craze, a popular dance style in the early part of the 20th century. Jazz artist Rudy Vallée became what was perhaps the first complete example of the 20th century mass media pop star. Vallée became the most prominent and, arguably, the first of a new style of popular singer, the crooner.