Ana Ivanovic and Novak Djokovic are singing a new tune. The top-ranked Serbs, now second and third in the world on their respective circuits, took a break from their preparations for Roland Garros to participate in a different kind of competition, the opening ceremonies of the 2008 Eurovision Song Competition, at the start of the week.

Djokovic appeared live in the host city of Belgrade for the event, while Ivanovic’s appearance was prerecorded.

On Tuesday, Djokovic helped host the first semi-final, and officially marked the start of the voting period by throwing a tennis ball into the audience before breaking out into song himself.

During a break in the second semifinal, a recorded feature was presented starring Ivanovic, who offered viewers a tour of her hometown of Belgrade.

The Eurovision Song Contest is an annual competition among members of the European Broadcast Union (EBU).  It is one of the longest-running television shows in history, premiering in 1956. The program has since been broadcast via the Eurovision television network in non-participating countries such as the United States, Canada, Mexico, South Africa, New Zealand, and Egypt among many others.

Beginning in 2000, it was also broadcast via the internet and is one of the most watched programs in the world, garnering over 100 million viewers each year. It is expected that the ratings for the final will break previous viewing records in Serbian television history.

The format of the event is also unique. Each participant selects a song which is performed by a citizen of that country. The performances of each nation are then voted on by other participating countries, but viewers cannot vote for singers of their own nationality.

The stage in Belgrade has been alive with fire, flashing lights, and costumed singers and dancers the entire week, all in a bid to win the Eurovision Song Contest 2008.

Serbia is the defending champion, which is gives it the honor of hosting this year’s competition. In 2007, 23-year-old Serbian pop singer Marija Serifovic sang the song “Molitva” in Helsinki to give Serbia its first crown.

The final took place on Saturday, May 24, between wining nations in the two semifinals with Russia’s Dima Bilan coming out on top with his rendition of “Believe!”