Raina Kabaivanska was one of the greatest sopranos of her generation -- arguably the greatest Tosca after Maria Callas. And even at 89, the Bulgarian singer is still a force in opera.
She may have given her last stage performance a decade ago, but her influence continues through the young stars she mentors through her annual masterclass in Sofia.
"When my career ended, I had this inner necessity to continue to be in the music," Kabaivanska -- who turns 90 in December -- told AFP.
"My life is music. Music gives you energy and inspiration and, above all, forms you as a person."
As her students took turns rehearsing their arias for this year's final gala concert in Sofia, Kabaivanska lip synched and gestured along in the shadows of the darkened hall.
Then suddenly, she left her seat, her arms delicately dancing to guide the singer through the most difficult parts.
"I am very old and absolutely I don't hide this. But this gives me great power to work with the young," Kabaivanska laughed.
"I have this ambition -- to set them on the right path."
Born in 1934 in the Black Sea city of Burgas, Kabaivanska learned piano as a child. Then a teacher at her high school in Sofia noticed her voice and included her in the choir.
She made her debut at the Sofia Opera in 1957 and two years later moved to Italy, where she performed at Milan's famous La Scala opera house, quickly making a name for herself.
She went on to bedazzle audiences around the world making roles such as Tosca and Madame Butterfly her own and sharing the stage with Spain's Placido Domingo and Italy's Luciano Pavarotti, a close friend and collaborator.
His family asked her to open the great tenor's funeral mass in 2007 in Modena, with Kabaivanska giving a particularly moving rendition of Verdi's "Ave Maria".
Strikingly beautiful, Kabaivanska was also a talented actor.
George Tekev was spellbound when as a nine-year-old he watched her play Queen Elisabeth in Verdi's "Don Carlos" half a century ago.
Twenty-five years later the academic invited her to give a masterclass at the New Bulgarian University (NBU).
"First and foremost, she is very inspiring, and she is a heavyweight. Maintaining such high standards requires a lot of effort," said the NBU's executive director of their long collaboration.
More than 200 students from all over the world have passed through the masterclasses Kabaivanska has taught every autumn since 2001 in Sofia.
Nearly half have continued to study with her at different schools in Italy with scholarships from a fund bearing her name.
Among those that have passed through "Kabaivanska school" are sopranos Maria Agresta from Italy, South Korean Vittoria Yeo and Ukrainian Sofia Soloviy, Italian tenor Andrea Care and South Korean baritone Simon Lim.
This year more than 90 singers turned up at the auditions for just 14 places.
"What is required is talent. Talent says it all," said Kabaivanska.
"Talent is not just natural abilities but also a capability to see the world in a different way. You are simply born to sing."
Even for the most talented, it is not easy to make a living "because art no longer holds the importance with the public that it had years ago," she said.
For student Baia Saganelidze, a 30-year-old mezzo-soprano from Georgia, the opera star "is teaching us everything -- how to sing, how to live, how to bring a certain role to the public."
"We always think about characters, the composer, every detail is discussed with her," Saganelidze told AFP.
Another student, Romanian bass Andrei Miclea, 25, said it was a "great honour" to be in the class.
"We learn from the maestra but we also learn from each other. We have a saying in this job -- 'You have to steal from everybody.'"
