Tributes are pouring in for Italian opera star Luciano Pavarotti, known as the King of High Cs in his heyday, who died Thursday at the age of 71.

"There were tenors, and then there was Pavarotti," said Italian film director Franco Zeffirelli about the singer who once hit nine high Cs in a row during a 1972 performance of "Daughter of the Regiment" at New York's Metropolitan Opera.

"There isn't a time when he comes on the radio that I don't swerve my car off the road so that I can just listen, because he truly is the voice of this century," Canadian classical soprano Measha Brueggergosman told Canada AM.

"It's a great loss. He was without doubt one of the most important tenors of all time. He was a wonderful man, a charismatic person. And a good poker player," fellow tenor Jose Carreras told the Swedish newspaper Expressen.

"I always admired the God-given glory of his voice -- that unmistakable special timbre from the bottom up to the very top of the tenor range," Placido Domingo said in a statement from Los Angeles.

"I also loved his wonderful sense of humor and on several occasions of our concerts with Jose Carreras -- the so-called Three Tenors concerts -- we had trouble remembering that we were giving a concert before a paying audience, because we had so much fun between ourselves."

Carreras, Pavarotti and Domingo performed at Rome's Caracalla Baths during the 1990 World Cup in Italy. "The Three Tenors," the recording of that performance, sparked an opera mini-boom.

Pavarotti's professional singing career began in earnest in 1963. His last public singing performance took place during the opening ceremony of the 2006 Winter Olympics in Turin.

He was diagnosed with pancreatic cancer and had surgery in July 2006 at a New York hospital to remove a tumour.

Pancreatic cancer is usually fatal, with only a four per cent survival rate five years after detection. Up to 80 per cent of those diagnosed with pancreatic cancer die within the first year.

The tenor underwent another two weeks of treatment last month, and was released from hospital in his hometown of Modena, Italy on Aug. 25. He was being attended to at home by cancer specialists up until his death at 5 a.m. local time.

Born on Oct. 12, 1935, he will be buried in Modena on Saturday.

Pavarotti's death comes the day after he received a new government award for his work in promoting Italian culture in Italy and abroad.

Milan's famous La Scala opera house, where Pavarotti first performed more than 40 years ago, said it would help organize a singing contest dedicated to the tenor.

"It is a precious chance to pay homage to the career of Luciano Pavarotti, a symbol of Italian music in the world," La Scala said in a statement. 

Beginnings

The son of a baker and amateur singer once said that his life was rich with happiness in spite of his family's modest circumstances.

"Our family had very little, but I couldn't imagine one could have any more," Pavarotti said.

Soccer pulled at Pavarotti, but he found himself enjoying listening to his father's recordings of tenor greats such as Jussi Bjoerling, Tito Schipa, and his favourite, Giuseppe Di Stefano.

He studied singing together with childhood friend Mirella Freni -- who eventually became a star soprano. The two ended up making records and performing in concerts together.

It was at the age of 20 when Pavarotti travelled with a chorus from his hometown to an international music competition in Wales. The group won first place, and from then on, Pavarotti dedicated his life to music.

His big break came in 1963, when he stood in for Di Stefano as Rodolfo at Covent Garden in London.

Global superstardom came in the 1970s. While some said Domingo might be the more complete singer, Pavarotti -- with his trademark smile -- had matchless charm.

"Every student, whether they were male or female, wanted to sound like Luciano. They wanted to have that presence, that charisma and that dynamism on stage," David Vizenten of the Glenn Gould School of Music told CTV Toronto.

But Pavarotti wasn't happy just singing at La Scala or the Met. He shared the stage with rock stars including Eric Clapton and U2's lead singer Bono, and even pop stars like the Spice Girls and Celine Dion.

Vizenten noted that Pavarotti's "popularist" appeal crossed generations and traditional boundaries.

Some memories that stick in his mind are the late comedian John Candy's satirical sketches of Pavarotti on the SCTV show and Pavarotti's own appearance on Sesame Street.

While Pavarotti's participation in the "Three Tenors" drew criticism from opera purists, the venture was hugely successful.

Each singer netted more than US$1 million from each concert, and their first album together sold some 20 million copies, making it the biggest-selling classical record of all time.

"The word commercial is exactly what we want," said Pavarotti after one of the Three Tenors concerts.

"We've reached 1.5 billion people with opera. If you want to use the word commercial, or something more derogatory, we don't care. Use whatever you want."

Pavarotti was also involved in charitable work. As a close friend of the late Diana, Princess of Wales, together they raised money to ban land mines worldwide.

He and Bono collected humanitarian aid during the Bosnia war, and he financed and established the Pavarotti Music Center in the Bosnian city of Mostar so the country's artists could have a chance to develop their skills.

Pavarotti's stumbles

While he had many good qualities, Pavarotti also had some weaknesses.

"Pavarotti is the biggest superstar of all," the late New York Times music critic Harold Schonberg once said. "He's correspondingly more spoiled than anybody else. They think they can get away with anything. Thanks to the glory of his voice, he probably can."

A controversial tell-all biography written by Pavarotti's former agent paints him as an enormously talented, but extraordinarily needy, artist.

In "The King and I," Herbert Breslin recounts his growing disappointment with Pavarotti as the singer's career, personal life and girth began to get out of control.

Breslin wrote about Pavarotti's numerous "secretaries" -- who would cater to his every need while his then-wife, Adua, sat and suffered at home in Modena.

Pavarotti divorced Adua after 37 years of marriage and married Nicoletta Mantovani, his personal assistant, in 1996. Mantovani was 34 years younger than himself and younger than his three daughters.

Accusations of tax evasion dogged the singer since the mid-1990s. He was accused in 1996 of filing false tax returns for 1989-91. In 2000 he agreed to pay nearly US$12 million to the Italian state after he claimed, unsuccessfully, that the tax haven of Monte Carlo, not Italy, was his official residence.

Pavarotti denied any wrongdoing, saying he paid taxes wherever he performed. Upon agreeing to the settlement, he stated: "I cannot live being thought not a good person."

With files from The Associated Press