'Fifth Beatle' George Martin dies at 90

Legendary British music producer George Martin, who turned the Beatles into the best-selling band in history, has died at the age of 90, his family said yesterday, as tributes poured in.

Beatles drummer Ringo Starr was the first to give the news, writing on Twitter: "God bless George Martin peace and love to Judy and his family... George will be missed," alongside a black-and-white picture of the "Fab Four" with Martin.

British Prime Minister David Cameron led praise for the producer, who signed up the young band from Liverpool when he headed the Parlophone label after hearing their demo record in 1962.

"Sir George Martin was a giant of music -- working with the Fab Four to create the world's most enduring pop music," Cameron tweeted.

Martin's innovative recording techniques and role as authoritarian mentor was so essential to the band's success that he was nicknamed the "Fifth Beatle".

 Martin produced 30 British number one singles, won six Grammys and was knighted by Queen Elizabeth II in 1996.

After the band split, Martin built the Air Studios on the Caribbean island of Montserrat and went on to work with other artists including Bob Dylan, Sting and Elton John.