Sir Paul McCartney was banned from performing in an empty room in case he ''upset'' people.

The Beatles legend was dining with his singer pal Adam Faith - who died in 2003 aged 62 - at the Royal Automobile Club when his friend spotted a grand piano and suggested he play 'Let It Be', but the impromptu rendition was quickly stopped by a member of staff.

They said: ''Sorry, you're going to have to stop that. You'll upset the members.''

According to a new biography of Faith, written by David and Caroline Stafford, the singer then protested most people would pay up to £10,000 to hear his friend perform in such an intimate setting.

The unimpressed staff member replied: ''I can't help that sir.''

To ensure the performance didn't continue, he then slammed down the piano lid and almost crushed McCartney's fingers.

In 2003, it was claimed the 'Hey Jude' hitmaker was paid $1 million for what was reported to be his first ever private concert, performing to 150 people in Sante Fe in honour of Wendy Walker Whitworth.

The 90-minute performance was a 50th birthday gift to Wendy from her husband, financier Ralph Whitworth, and all proceeds went to charity.