VIENNA (AP) — At the Eurovision Song Contest, performers get three minutes to make a big impression.

Grabbing viewers’ attention as one of 25 acts competing in quick succession in Saturday’s grand final in Vienna means pulling out all the stops, both musically and visually.

In the case of this year’s favorites to win, the Finnish duo of pop singer Pete Parkkonen and classical violinist Linda Lampenius, that involves jets of flame, a valuable 18th-century violin and a team of “ninjas” working to avert disaster.

The pair’s song “Liekinheitin,” or “Flamethrower,” is a favorite with both fans and betting markets with its melding of pop and classical influences — and its spectacular staging.

Here’s what it takes to create the eye-catching performance.

Permission to play

Parkkonen and Lampenius dub their sound “new pop with a classical touch.” Their song of burning love is an explosion of energy in which Parkkonen’s passionate vocals act as counterpoint to Lampenius’ frenetic fiddling.

The Finnish delegation had to secure special permission for Lampenius to play live. Eurovision rules state that lead vocals must be performed live, but instruments are prerecorded, to help speed changeovers between songs.

Lampenius says “Flamethrower” was “written as a duet,” and both performers need to be live for it to work.

“It’s a woman and a man, it’s a female voice and a male voice. So I do all my lyrics through my violin, by playing, and you (Parkkonen) are singing it with words. But we are talking. We are (equally) as important, both of us.”

The pair were not certain when they arrived in Vienna that Eurovision organizers would allow the request. They were only given final approval after performing in front of an audience in a live rehearsal.

The European Broadcasting Union, which runs Eurovision, said contest rules allow that “live audio capture of instruments may exceptionally be permitted where artistically justified.”

Lampenius had brought two violins just in case – a treasured Gagliano made in 1781 so live performance would “sound perfect,” and a cheaper instrument to use if she had to rely on playback. That would remove any risk to the Gagliano from the slightly hazardous staging.

Practice makes perfect

Lampenius and Parkkonen say they have been rehearsing for this moment since November. They won Finland’s national selection contest for Eurovision in February and say by now they have performed the song hundreds of times.

It is crucial to get it right. The performance builds to a climax that sees jets of flame spurt from a stage on which Lampenius, fanned by a leaf blower and wearing a flowing dress, is playing her precious violin.

Lampenius concedes it’s “a bit scary when you think of it.”

But she says she is secure in the knowledge she has black-clad stagehands who call themselves “ninjas” on hand to keep her dress away from the flames – an essential piece of the performance that goes unseen by viewers watching at home.

“They’re running with me – first one guy carrying my dress when I’m running, then the other one catching me during my run,” she said. “And he helps me also when I jump up on the stage and do the pirouette.”

For the striking final pose in which Lampenius perches atop chairs in high heels, violin aloft, Parkkonen combines singing with his role as a security spotter, there to catch her if she topples over.

“That’s my work,” the singer said.