Stephen Sondheim, the songwriter who reshaped American musical theatre in the second half of the 20th century with his intelligent, intricately rhymed lyrics, his use of evocative melodies and his willingness to tackle unusual subjects, has died. He was 91.

Sondheim’s death was announced by Rick Miramontez, president of DKC/O&M. Sondheim’s Texas-based attorney, Rick Pappas, told The New York Times the composer died Friday at his home in Roxbury, Conn.

Sondheim influenced several generations of theatre songwriters, particularly with such landmark musicals as CompanyFollies and Sweeney Todd, which are considered among his best work. His most famous ballad, Send in the Clowns, has been recorded hundreds of times, including by Frank Sinatra and Judy Collins.

The artist refused to repeat himself, finding inspiration for his shows in such diverse subjects as an Ingmar Bergman movie (A Little Night Music), the opening of Japan to the West (Pacific Overtures), French painter Georges Seurat (Sunday in the Park with George), Grimms’ fairy tales (Into the Woods) and even the killers of American presidents (Assassins), among others.

“The theatre has lost one of its greatest geniuses and the world has lost one of its greatest and most original writers. Sadly, there is now a giant in the sky. But the brilliance of Stephen Sondheim will still be here as his legendary songs and shows will be performed for evermore,” producer Cameron Mackintosh wrote in tribute.

Six of Sondheim’s musicals won Tony Awards for best score, and he also received a Pulitzer Prize (Sunday in the Park), an Academy Award (for the song Sooner or Later from the film Dick Tracy), five Olivier Awards and the U.S. Presidential Medal of Honour. In 2008, he received a Tony Award for lifetime achievement.

Sondheim’s music and lyrics gave his shows a dark, dramatic edge, whereas before him, the dominant tone of musicals was frothy and comic. He was sometimes criticized as a composer of unhummable songs, a badge that didn’t bother Sondheim.

To theatre fans, Sondheim’s sophistication and brilliance made him an icon. A Broadway theatre was named after him. A New York magazine cover asked: “Is Sondheim God?” The Guardian newspaper once offered this question: “Is Stephen Sondheim the Shakespeare of musical theatre?”

He offered the three principles necessary for a songwriter in his first volume of collected lyrics: Content dictates form; less Is more; and God is in the details. All these truisms, he wrote, were “in the service of clarity, without which nothing else matters.” Together they led to stunning lines like: “It’s a very short road from the pinch and the punch to the paunch and the pouch and the pension.”

Taught by no less a genius than Oscar Hammerstein, Sondheim pushed the musical into a darker, richer and more intellectual place. “If you think of a theatre lyric as a short story, as I do, then every line has the weight of a paragraph,” he wrote in his 2010 book, Finishing the Hat, the first volume of his collection of lyrics and comments.

Penned theatre classics

Early in his career, Sondheim wrote the lyrics for two shows considered to be classics of the American stage, West Side Story (1957) and Gypsy (1959). West Side Story, with music by Leonard Bernstein, transplanted Shakespeare’s “Romeo and Juliet” to the streets and gangs of modern-day New York. Gypsy, with music by Jule Styne, told the backstage story of the ultimate stage mother and the daughter who grew up to be Gypsy Rose Lee.

It was not until 1962 that Sondheim wrote both music and lyrics for a Broadway show, and it turned out to be a smash — the bawdy A Funny Thing Happened on the Way to the Forum, starring Zero Mostel as a wily slave in ancient Rome yearning to be free.

U.S. composer and lyricist Stephen Sondheim is seen in August 1962. (Michael Hardy/Express/Getty Images)

Yet his next show, Anyone Can Whistle (1964), flopped, running only nine performances but achieving cult status after its cast recording was released.

It was Company, which opened on Broadway in April 1970, that cemented Sondheim’s reputation. The episodic adventures of a bachelor (played by Dean Jones) with an inability to commit to a relationship was hailed as capturing the obsessive nature of striving, self-centred New Yorkers. The show, produced and directed by Hal Prince, won Sondheim his first Tony for best score. The Ladies Who Lunch became a standard for Elaine Stritch.

The following year, Sondheim wrote the score for Follies, a look at the shattered hopes and disappointed dreams of women who had appeared in lavish Ziegfeld-style revues. The music and lyrics paid homage to great composers of the past such as Jerome Kern, Cole Porter and the Gershwins.

In 1979, Sondheim and Prince collaborated on what many believe to be Sondheim’s masterpiece, the bloody yet often darkly funny Sweeney Todd. An ambitious work, it starred Cariou in the title role as a murderous barber whose customers end up in meat pies baked by Todd’s willing accomplice, played by Angela Lansbury.

Sondheim presents Tim Burton, who directed a film adaptation of Sweeney Todd, with an award in New York City in January 2008. (Lucas Jackson/Reuters)

Sunday in the Park, written with James Lapine, may be Sondheim’s most personal show. A tale of uncompromising artistic creation, it told the story of artist Georges Seurat, played by Mandy Patinkin. The painter submerges everything in his life, including his relationship with his model (Bernadette Peters), for his art.

Three years after Sunday debuted, Sondheim collaborated again with Lapine, this time on the fairy-tale musical Into the Woods. The show starred Peters as a glamorous witch and dealt primarily with the turbulent relationships between parents and children, using such famous fairy-tale characters as Cinderella, Little Red Riding Hood and Rapunzel.

Troubled family life

Sondheim was born March 22, 1930, into a wealthy family, the only son of dress manufacturer Herbert Sondheim and Helen Fox Sondheim. At 10, his parents divorced and Sondheim’s mother bought a house in Doylestown, Pa., where one of their Bucks County neighbours was lyricist Oscar Hammerstein II, whose son, James, was Sondheim’s roommate at boarding school. It was Oscar Hammerstein who became the young man’s professional mentor and a good friend.

He had a solitary childhood, which involved verbal abuse from his chilly mother. He received a letter in his 40s from her telling him that she regretted giving birth to him. He continued to support her financially and to see her occasionally but didn’t attend her funeral.

In September 2010, the Henry Miller Theatre was renamed the Stephen Sondheim Theatre. “I’m deeply embarrassed. I’m thrilled, but deeply embarrassed,” he said as the sun fell over dozens of clapping admirers in Times Square. Then he revealed his perfectionist streak: “I’ve always hated my last name. It just doesn’t sing.”