Over the past 100 years or so, American popular music has gained acceptance at home and abroad. It has become the music that many, especially the young and young at the heart, listen to virtually all of the time. In the United States, the vast array of popular music forms are aired by more than 90 percent of all radio stations. Internationally, both American versions of popular songs and versions in native tongues permeate the air waves. Indeed, many American artists enjoy prolonged careers by marketing themselves in other countries well after their popularity has waned in the US.