Stephen Sondheim was born in 1930 in New York.
He started playing the piano at the age of seven and at the age of ten he received a mentor in the musical legend Oscar Hammerstein via his son James, who was his school friend and close friend.
Hammarstein co-wrote some of the world's most famous musicals with songwriting partner Richard Rodgers, including "Oklahoma!"
and "The sound of music".
The first success came in 1957, when Sondheim was commissioned to write the lyrics to Leonard Bernstein's "West side story".
Has been awarded eight Tony statuettes
The first Broadway musical with both music and lyrics by Stephen Sondheim was "A fun thing happened on the way to the Forum", from 1962. His most productive time was the 1970s and 80s.
During his career, he was awarded a total of eight Tony statuettes, among them a Lifetime Achievement Award, and an Oscar.
Sondheim's last musical, "Road show", premiered on Broadway in 2008 (it had been played in theaters "off Broadway" since 1999).
In 2015, he received the President's Freedom Medal from Barack Obama.
Stephen Sondheim turned 91 years old.