ASCAP and BMI, the two top music performing rights organizations in the United States, have issued lists of the most-performed songs of the 20th century. Owners of a song's copyright are paid a small amount each time a song is publicly performed or broadcast, and both ASCAP and BMI are companies that license and track the public performances of music for the writers and publishers they represent.

Easily topping the ASCAP list is ''Happy Birthday to You,'' which ASCAP says has been performed hundreds of millions of times this century. The song was written by sisters Mildred J. Hill and Patty Hill in the 1890s as ''Good Morning To You,'' and was copyrighted with the birthday lyrics in 1935.

The BMI list, which ranks the songs most played on radio and television, is led by ''You've Lost That Lovin' Feelin','' written by Barry Mann, Phil Spector and Cynthia Weil. The song, which recently passed the 8 million performance plateau, was originally recorded by the Righteous Brothers and producer by Spector.

The second, third and fourth songs on the BMI list all have been aired more than 7 million times, and the remainder of the top 10 have aired more than 6 million times, according to a press release from the organization. The top 10 songs on BMI's list are listed below, and a list of the top 100 songs is available at BMI's official website..