To mark his 80th birthday year, musical theatre legend Stephen Sondheim appraises his long career and dissects his own lyrics from West Side Story to Sweeney Todd.

In today's episode, Sondheim recounts his experience of writing the lyrics for Gypsy - and of working with the indomitable Ethel Merman.

In Finishing the Hat - a title borrowed from one of his most autobiographical songs - Sondheim has not only collected his lyrics for the first time, but has provided a forensic account of the lyric-writing process.

As he discusses the lyrics for several of his major musicals from 1954 to 1981-including West Side Story, Gypsy, Company, A Little Night Music and Sweeney Todd-Sondheim offers an illuminating insight into the lyric-writer's art, as well as a number of warm and witty anecdotes about the remarkable figures with whom he has worked.

He discusses his relationship with his mentor, Oscar Hammerstein II, and his collaborations with extraordinary talents such as Leonard Bernstein, Arthur Laurents, Jule Styne, Ethel Merman and Harold Prince.

Penetrating and self-deprecating, thoughtful and witty, Finishing the Hat is not only an informative look at the art and craft of lyric writing, it is also a window on musical theatre history since the 1950s.

Additional readings by Juliet Stevenson

Produced by Emma Harding. Show less