Impresario Sir Cameron Mackintosh has told BBC News Online he is spending £35m to rejuvenate London's West End to "make it exciting and new".
Impression of proposed Queen's, Gielgud and Sondheim theatres
Sir Cameron announced on Wednesday he was to build a new theatre, The Sondheim, and revamp six of his other venues in an effort to boost dwindling audiences.
Unveiling the project on Wednesday, Sir Cameron urged people who had stayed away from London's theatres to return.
He told BBC News Online: "As long as people keep writing great new plays and put on great new productions, the West End is alive and well.
Queen's Theatre: Whole building will be redesigned, it will gain 200 seats and a new shared foyer with the adjacent Gielgud Theatre
Sondheim: New 500-capacity venue above the Queen's
Prince of Wales: £7m being spent on refurbishment of Coventry Street theatre
Also being revamped:
Strand, Wyndham's and Albery: £1.7m restoration, and improvements to access and the venues' bars
"Myself and many of my colleagues will be continuing to make the theatre great fun and one of the few things you can't do in the privacy of your living room."
Baz Bamigboye, the Daily Mail's showbiz columnist, said he believed the plan could help to regenerate the West End.
"Cameron is first and foremost a showman. He's very shrewd in that way and he will get people more interested," he said.
But Geoffrey Marsh, director of the Theatre Museum, warned that more needed to be done to improve infrastructure.
He said: "With the government's Olympics bid, a lot of energy needs to go into creating a central London we can be proud of."
Sir Cameron, producer of worldwide hits such as Les Miserables, Phantom of the Opera and My Fair Lady, is sinking a percentage of his estimated £300m personal fortune into the venture.
He has been an outspoken critic of the West End's traffic congestion, poor public transport and the threat of street crime.
Sir Cameron said although said these problems would not go away overnight, the situation was improving.
"As a private individual I'm doing what I can to make it better," he said.
"In the end what puts bums on seats is a hit. But the West End itself needs to be a hit, and a great place to go for a show, a beer, a party or a club."
Sir Cameron, who also owns the Prince Edward theatre, said his dream was to extend the life of his venues for at least another 100 years.
Sir Cameron says the West End has been in decline
"What we'll do to reinvent them for the 21st Century will give them a new lease of life," he said.
Sir Cameron's Sondheim Theatre - named after US composer and lyricist Stephen Sondheim - will be the first new theatre in Shaftesbury Avenue for more than 70 years.
It will be built above his Queen's Theatre - which will itself be remodelled when work begins in 2006.
Some £20m is being invested in redesigning the block on Shaftesbury Avenue housing the Queen's and the Gielgud Theatre.
They will get a communal foyer, and an extra 200 seats will be added to the Queen's.
The 500-capacity Sondheim will take extended runs of musicals and plays transferred from other leading smaller theatres such as the Almeida, Donmar Warehouse and Cottesloe.
Impression of proposed Prince of Wales auditorium
Stephen Sondheim said he was thrilled to have had his name attached to the venture.
He said: "The news that the West End is at last getting
a theatre that can take transfers of productions from Britain's subsidised
studio playhouses for extended runs is thrilling indeed for British writers and
Sir Cameron plans to spend another £7m refurbishing his Prince Of Wales theatre.
Its façade and entrances will be improved, leg room and seating upgraded, and the auditorium rebuilt and decorated in gold, bronze and copper to give it a more lavish look.