The American composer and lyricist, who has died aged 91, shaped the musical artform with his wise, witty and extravagantly clever work

Stephen Sondheim achieved such acclaim – for deepening the content and extending the lyrical ingenuity of musical theatre – that, from the age of 50, each major birthday was celebrated with tribute concerts in London, New York or both.

Watching the composer-lyricist of Sweeney Todd and Follies at such events – taking a bow, with his wry smile – it was impossible not to reflect on our luck in coinciding with the life of someone who would clearly stand in the history of the genre alongside such geniuses as Cole Porter, Irving Berlin, George and Ira Gershwin, Leonard Bernstein, Kurt Weill, Richard Rogers and Oscar Hammerstein.