Sir George Martin, the record producer, dubbed the 'Fifth Beatle', has died aged 90.

Beatles drummer Ringo Starr announced the news on Twitter, writing: “God bless George Martin peace and love to Judy and his family love Ringo and Barbara. George will be missed.”

Sir George helped The Beatles achieve global success as the head of the Parlophone record label after hearing their demo tape in 1962.

He captioned a picture of the Fab Four and Sir George with the phrase: “Thank you for all your love and kindness George peace and love.”

Sean Ono Lennon, son of John and Yoko, also paid tribute, saying: "I'm so gutted I don't have many words."

Liam Gallagher tweeted: "Sir George Martin RIP LG x".

Singer Lenny Kravitz wrote on Twitter: “The legends are really going home! Visionary producer of TheBeatles, George Martin (1926-2016).”

Fellow music producer Quincy Jones, who is best known for co-producing several of Michael Jackson's albums, said he had been friends with Martin since 1964.

Singer Josh Groban said: “Every time I record at abbey road I geek out and play with the mics sir George Martin used. What an ear, what a life, what a legacy.”

DJ and producer, Mark Ronson called Martin the "greatest British record producer of all time" while Boy George said he was a "gentleman" and a "legend".

Sir Roger Moore credited Martin for making his first Bond film sound "brilliant". He was, of course, referring to Live and Let Die for which Martin wrote the score and composed the arrangement for Sir Paul McCartney's iconic title theme song.

Television presenter Piers Morgan said: “RIP Sir George Martin. The 5th Beatle, producer extraordinaire & a musical genius.”

Prime Minister David Cameron also paid tribute online, writing: “Sir George Martin was a giant of music - working with the Fab Four to create the world's most enduring pop music.”

In 1962, it was a phone call from music publisher Syd Coleman which changed the course of Sir George's life.

Coleman said he had met a man called Brian Epstein, who managed a new band called The Beatles, and would Martin be interested in hearing their demo?

George Martin: Life in pictures Show all 15 1 /15 George Martin: Life in pictures George Martin: Life in pictures 1963 The Beatles at a recording session for the Parlophone label with their producer George Martin Getty Images George Martin: Life in pictures April 1963 The Beatles hold their silver disc. (L-R) Paul McCartney, George Harrison, Ringo Starr, George Martin of EMI and John Lennon Getty Images George Martin: Life in pictures 1965 Sir George Martin, British record producer and composer is sometimes referred to as 'the Fifth Beatle', owing to his production work on all but one of The Beatles' original albums Getty Images George Martin: Life in pictures May 1968 George Martin with Cilla Black, whose single 'Work Is A Four Letter Word' he produced Getty Images George Martin: Life in pictures June 1999 The Bangles with Beatles producer, Sir George Martin at the Hollywood Bowl where the band performed 'Roll Over Beethoven' conducted by Martin. From l-r: Michael Steele, Vicki Peterson, Sir George Martin, Suzanna Hoffs and Debbi Peterson Getty Images George Martin: Life in pictures March 1999 Rock and Roll Hall of Fame inductee Sir George Martin holds up his statue during the 15th Rock and Roll Hall of Fame Induction Ceremony in New York George Martin: Life in pictures February 2001 Beatles' producer George Martin during a press conference at the European Parliament in Strasbourg Getty Images George Martin: Life in pictures September 2002 Sir George Martin speaks during the launch of Windows Media 9 Series in Hollywood Getty Images George Martin: Life in pictures October 2002 Sir George Martin shares a seat with a statue of John Lennon in a park of Havana, Cuba. Martin made a visit to Cuba to offer conferences on the Beatles and to participate in concerts with Cuban musicians Getty Images George Martin: Life in pictures May 2006 Music directors Giles Martin (L) and Sir George Martin (R) speak at the media viewing of The Beatles 'Love' by Cirque du Soleil at The Mirage in Las Vegas Getty Images George Martin: Life in pictures June 2006 Musical directors Giles Martin (L) and his father Sir George Martin joke around during a behind-the-scenes tour of 'The Beatles LOVE by Cirque du Soleil' at The Mirage Hotel & Casino in Las Vegas Getty Images George Martin: Life in pictures June 2006 Sir George Martin arrives with his wife Judy Lockhart Smith at the gala premiere of 'The Beatles LOVE by Cirque du Soleil' at The Mirage Hotel & Casino in Las Vegas Getty Images George Martin: Life in pictures November 2006 (L-R) CEO of EMI Tony Wadsworth, Producer Sir George Martin and his son Giles and Paul Gambaccini are seen at the Launch of the New Beatles Album, 'Love' at Abbey Road Studios in London Getty Images George Martin: Life in pictures February 2008 Musician Ringo Starr of the Beatles, Beatles producer Sir George Martin and producer Giles Martin accept the Best Compilation Sountrack Album award for 'Love' onstage during the 50th annual Grammy awards held at the Staples Center in Los Angeles Getty Images George Martin: Life in pictures June 2011 Sugar Ray singer and television personality Mark McGrath (L) greets music producer Sir George Martin as they arrive at the fifth anniversary celebration of 'The Beatles LOVE by Cirque du Soleil' show at The Mirage Hotel & Casino in Las Vegas Getty Images

When Martin heard the tape - which featured versions of “Besame Mucho” and “Three Cool Cat”s, as well as originals such as “Hello Little Girl” and “Like Dreamers Do” - and went on to meet them, he realised their potential.

“I liked them as people apart from anything else, and I was convinced that we had the makings of a hit group,” he said.

But he was not convinced they had songwriting ability.

“As composers, they didn't rate. They hadn't shown me that they could write anything at all,” he told Melody Maker. “'Love Me Do' I thought was pretty poor, but it was the best we could do.”