President Barack Obama and music mogul Simon Cowell paid tribute to American Idol as the talent show aired its final episode on US television.
Cowell, who appeared as judge on the hugely popular programme for nine seasons, was a surprise guest as a host of former winners performed at the Dolby Theatre in Los Angeles.
American Idol, which launched the careers of international stars Kelly Clarkson, Jennifer Hudson and Carrie Underwood, bowed out after 15 series. It first aired in 2002.
During the final moments of the show, Cowell joined his fellow original judges Paula Abdul and Randy Jackson on stage with presenter Ryan Seacrest.
"Thank-you America for inviting us into your homes," he said.
"Without the fans there would be no show.
"I'm feeling quite emotional now."
Obama was the unexpected opening act as he congratulated the show on its long run, and he noted that it motivated millions of young people to vote for contestants.
In a pre-recorded segment, he called for Americans to show the same eagerness at the polls.
"I believe it should be almost as easy as voting on American Idol. And we're working on that," he said.
Trent Harmon defeated La'Porsha Renae to be crowned winner of the final series.