Sondheim, 91, was an unquestionable giant among American musical masters -- among them, Porter, Berlin, Bernstein and the Gershwins, as well as Richard Rogers and the man considered his surrogate father, Oscar Hammerstein.
His death, following Thanksgiving with family at his Roxbury, Connecticut home, brought expressions of grief, love and deep appreciation.
"Farewell Steve, the musical theatre giant of our times, an inspiration not just to two but to three generations," Andrew Lloyd Weber tweeted. "Your contribution to theatre will never be equaled."
"There are no words. He had them all. And the music," the Sondheim Society wrote. "He was incomparable. He was God to many of us. We loved his work. And god he was good. So good."
Think about it: "West Side Story," "Sweeney Todd," "Into the Woods," "Company," "A Little Night Music" -- Sondheim's musical genius made them classics.
And the songs -- led perhaps by (depending on your preference) "Send In The Clowns."
Many considered Sondheim the greatest composer and lyricist of the 20th century. Some called him "the most important man in musical theatre."
Legendary theater Frank Rich once wrote that Sondheim "changed the texture of the musical as radically as Oscar Hammerstein, and may yet leave our theatre profoundly altered.”
Indeed, Sondheim himself once said that he created his musicals "to make people laugh and cry and think."
Sondheim garnered the highest of accolades through a celebrated career spanning more than six decades -- the Tony Awards and Grammy Awards (eight each), an Oscar, a Kennedy Center honor, the Presidential Medal of Freedom and a Pulitzer Prize.
Those who knew him said he may have been most tickled by the annual birthday tributes in concerts on either side of the pond that began when Sondheim turned 50.
“I am the best laugher,” he told The Guardian in 2000. “If you write a comedy, hire me to sit in the audience...although I tend to guffaw, which is not always great.”
A New York City native and only child, Sondheim spent his early years on Manhattan's Upper West Side and attended the Ethical Culture Fieldston School. He was 10 when his parents divorced and he moved with his mother to a farm near Doylestown, Pennsylvania.
He then befriended James Hammerstein, whose legendary dad became the young prodigy's mentor.
It was a meteoric rise from there.
Sondheim's very first Broadway production, “A Funny Thing Happened on the Way to the Forum” (1962), won a Tony for best musical. Its run lasted more than two years.
The Seventies opened with "Company" and closed with "Sweeney...," with several other smashes in between. Meanwhile, the honors continued to accumulate.
In celebration of his 80th birthday, the former Henry Miller's Theatre on West 43rd Street was renamed the Stephen Sondheim Theatre in 2010.
A fall prevented Sondheim from attending the opening of a namesake theater in London's West End last year.
He took it in stride.
“As I recover from my tumble, I’m impatient to throw away my cane, grab my hat and head across the Pond as soon as I can to see on which cherub Cameron has tattooed my initials,” Sondheim said in a statement at the time. “I am, to put it mildly, chuffed to have my name on a theatre in the West End I have loved visiting ever since my first trip to London almost seventy years ago.”
Sondheim turned 91 this past April.
“Gosh. I’m sure we all knew this wasn’t far off but it still hits," tweeted “Wicked” actress Alice Fern. "You were a Titan and your work lives on sir. God bless ya Stephen Sondheim. Thank you #sondheim.”
“We shall be singing your songs forever," wrote “Miss Saigon” star Lea Salonga. "Oh, my heart hurts…”
Actress Uzo Aduba called Sondheim "the best there ever was. I don’t know when we will ever have another of his caliber, of his breadth and scope. Just the greatest, a legend, a true titan."
"You gave us something new," tweeted actor/comedian Mario Cantone. "You changed the game. I was so lucky."
As were countless others.
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