Spanish tenor Placido Domingo (left) and Russian soprano Anna Netrebko (right) perform during a rehearsal of Giuseppe Verdi's Il Trovatore. Photo: IC

The struggling Salzburg Festival saw its cultural and commercial highlight of the year Saturday with the eagerly awaited new production of Verdi's opera Il Trovatore, 2014's hot ticket.

Featuring the world-famous Placido Domingo, now more a baritone than tenor at 73, and Russian soprano sensation Anna Netrebko, demand for the premiere outstripped supply five times over.

Directed by Alvis Hermanis, conducted by Daniele Gatti and also starring Canadian contralto Marie-Nicole Lemieux, five further showings over the next two weeks are also sold out.

Other expected hits among the performances at the festival, this year with a war theme for the 1914 centenary, include Chinese pianist Lang Lang and conductor Sir Simon Rattle.

But not all the tickets - some costing hundreds of euros - for the month-long extravaganza of opera, classical music and drama in Mozart's native city sell like hot cakes.

The annual shindig, in its 94th edition, is facing budget strains with too few spectators in recent years to cover the sometimes exorbitant costs of singers, sets, musicians and costumes.

This is despite last year's edition shifting 287,000 tickets and attracting record levels of corporate sponsorship.

Festival director Helga Rabl-Stadler has promised belt-tightening with fewer brand new productions and more recycled old ones in the future. She also wants to attract more public funding.

"I cannot stay silent any longer... We need substantially more funding," she said in April. "What is at stake here is the very existence of the Salzburg Festival."

Il Trovatore was last seen in Salzburg in 1963 under legendary Austrian conductor Herbert von Karajan, giving the class of 2014 big shoes to fill for what is anyway a challenging opera to stage.