Andrew Lloyd Webber's collection of art by Picasso, Canaletto and Rossetti is to go on public display for the first time.
Lloyd Webber has made millions from shows like Cats
The multi-millionaire theatre producer will lend 200 pieces to the Royal Academy in London for exhibition in September.
His collection is described as one of the finest in private hands, accumulated after he developed a passion for Victorian art at an early age.
The exhibition had been due to be held in several years' time but has been brought forward after another show was cancelled.
A major exhibition of Egyptian art was shelved by the gallery because of "political instability in the Middle East".
The Academy's exhibitions secretary Norman Rosenthal said cancellation of the Egypt exhibition had been more of a precautionary measure.
"We were worried that something could go wrong in the circumstances of the instability in the Middle East.
"The idea of being rung up in July, when I'm lying on a beach, saying there's no exhibition in September for whatever reason, it was too risky."
He said the authorities in Egypt were still keen for the treasures to be seen - probably next year - particularly because of the collapse of tourism in their own country.
Lord Lloyd-Webber owns at least 15 Rossettis as well as Picasso's masterpiece Angel Fernandez de Soto and Canaletto's Old Horseguard's Parade.
Other works in his collection include Sir Joshua
Reynolds's Portrait of George IV and Stanley Spencer's Self-Portrait and On the Tiger Rug.
"It will be fantastic to see the collection together in one place in this way," he said.
"I sincerely hope that it will give as much pleasure to those who visit the exhibition as it has given me, my family and friends, over many years."
Lloyd Webber has made an estimated £400m from shows including Cats, Starlight Express and Phantom of the Opera.