Two children of an Oscar-winning composer, who left his house to a friend and carer who "rescued him", are challenging his will in the High Court.
Sir Malcolm Arnold was an alcoholic living in a pub in Northamptonshire in 1984 when Anthony Day "saved him from oblivion", the court heard on Monday.
Katherine and Robert Arnold claim their father, who died in 2006 aged 84, was subjected to "undue influence".
Mr Day's barrister, Tom Dumont, said Sir Malcolm knew what he was doing.
The Northampton-born composer, who wrote the score to the 1957 film Bridge Over the River Kwai, had been made a ward of the Court of Protection when Mr Day stepped in, the court heard.
'Gave life back'
The neighbour of a distant relative, Mr Day went on to live with and care for Sir Malcolm in Attleborough, Norfolk.
There was no question Sir Malcolm had legal capacity when he signed a 1990 will leaving Mr Day his house, his valuable manuscripts and a half share in the annual royalties from his work, Judge Charles Purle QC was told.
As a result of Mr Day's help, Sir Malcolm had overcome his alcoholism, wrote music again, and was knighted in 1993, Mr Dumont added.
They were not lovers but in an earlier will the composer had described Mr Day as the man who "gave me back my life and work when no-one cared", said the barrister.
He made cash gifts to his friend to take advantage of inheritance tax breaks and gave him manuscripts, one of which may have been worth £50,000, the court heard.
Mr Dumont said of the evidence in the case: "It does not show a man who is taking advantage of every opportunity to take money out of the estate of Sir Malcolm."
When Sir Malcolm became ill in 2003, Ms Arnold reported Mr Day to the police for allegedly abusing his charge, and made "disingenuous" and "gratuitously offensive" accusations, Mr Dumont said.
Her attempt to have Sir Malcolm brought back under the Court of Protection was later dismissed by a senior court official who found she had "acted malevolently", the court heard.
Mr Dumont said there was "no backlash" against Ms Arnold, who remained a beneficiary of her father's will.
The hearing, expected to last several days, continues.