The music to Alfred Hitchcock's Psycho is one of the most iconic ever written. And the original autographed score is now for sale - for £50,000.

Norma Herrmann, widow of the composer Bernard Herrmann, is marking the centenary of his birth by selling the manuscript to help fund a proposed recording project of his work.

Bernard Herrmann, the son of an American Jewish family of Russian origin, died aged 64 in 1975. He composed the music for Orson Welles's Citizen Kane, Alfred Hitchcock's Vertigo and Martin Scorsese's Taxi Driver.

The music for Psycho is perhaps his most recognised. He chose to write only for strings, thereby complementing the film noir qualities of Hitchcock's film with a suitably monochrome aural counterpart.

Hitchcock initially planned a complete absence of music during Psycho's famous shower scene. He changed his mind, and so effective was the music in this scene that the censor told Herrmann that if anything in the film needed cutting, it was his screeching strings, echoing the stabs of the murder.

Mrs Herrmann recalled: "The censor said he had worked out that what was unacceptable was the music, and he looked into whether he could censor it."

Fortunately, there was no precedent to edit out music and so the score remained intact.

Norma Herrmann first met her future husband in his native New York, sharing a taxi on New Year's Eve, 1966. She became Herrmann's third wife a year later, when he was 56 and she was 27. Herrmann kept a house in Hollywood, where he worked, but lived in London from the 1960s.

Goody's Original Kosher Restaurant on Berwick Street, now long gone, was his favourite London eaterie.

Mrs Herrmann, who has lived in Brighton for 30 years, was a producer and reporter on Esther Rantzen's TV show, That's Life, for 21 years.

Now 70, she is passionately committed to preserving her husband's legacy, which is why she has previously sold manuscripts of his work to the University of California.

There, they are available to students, historians, and musicologists. With the proceeds of the Psycho sale, she plans to fund a compilation boxed-set of all his works, to help her husband's music reach a wider audience, including many lesser-known compositions not written for films.

The Psycho score is the last memento of her husband's work she has kept.