The new trust is sponsoring a BBC Orchestra performance

Lean Scully, who died last year, had been a regular for the last decade at classical concerts staged by the Edinburgh International Festival (EIF).

Ms Scully promised the EIF she would "see them right" when she had gone.

But no one expected the 5.5 million euro bequest - the biggest single gift in the festival's 60-year history.

While she was alive, Ms Scully gave �45 a year to the EIF.

The legacy was from the sale of two homes next to one another in Dublin owned by Ms Scully, who worked in agricultural public relations.

Some said she was lonely but she was a big party-goer, she loved to have a drink Sir Brian McMaster EIF director

The money will be invested, as she intended, in a trust which will yield �150,000 a year in interest for promoting the careers of young artists.

Sir Brian McMaster, director of the EIF, which opens on Sunday, said: "This is the type of bequest arts organisations dream about.

"Lean's been a regular visitor to the festival for the last 10 years. She was very passionate about the arts.

"She left us the residue of her estate, after gifts to friends, which is two Dublin homes.

"Of course, property values in Dublin have rocketed over the past few years, so the homes were worth quite a lot of money."

Reported deficit

He said Ms Scully loved coming to the Usher Hall to see performances and was a lovely person but he had no idea of her wealth.

"She had a wonderful turn of phrase. Some said she was lonely but she was a big party-goer, she loved to have a drink," he added.

Ms Scully also went on trips run for festival supporters to the St Magnus Festival in Orkney and the Wexford Festival.

The extra cash will be welcomed - the EIF has an �8m budget, but reported a �1m deficit earlier this year.