The Web site said the pop singer, who is embracing country music on her newest album, was a surprise visitor to the annual celebration of the country music genre.

Simpson's appearance at Wednesday's festivities came as the singer's first single from her new album has been in rotation around the country.

Keith Kaufman, the program director for WSIX-FM, Nashville, said the single "Come on Over" was comparable to works by country star Carrie Underwood.

"This is as good as any Carrie Underwood song," Kaufman said.

One person who was not in attendance at the CMA gathering was Dallas Cowboys quarterback Tony Romo, who has been linked romantically linked to Simpson.

Usmagazine.com said Simpson's father Joe interfered with the relationship and attempted to influence the NFL star's sports career during their relationship.