David Bowie, the infinitely changeable, fiercely forward-looking songwriter who taught generations of musicians about the power of drama, images and personae, died on Sunday, two days after his 69th birthday.

Mr. Bowie’s death was confirmed by his publicist, Steve Martin, on Monday morning.

He died after an 18-month battle with cancer, according to a statement on Mr. Bowie’s social-media accounts.

“David Bowie died peacefully today surrounded by his family,” a post on his Facebook page read.

His last album, “Blackstar,” a collaboration with a jazz quintet that was typically enigmatic and exploratory, was released on Friday — on his birthday. He was to be honored with a concert at Carnegie Hall on March 31 featuring the Roots, Cyndi Lauper and the Mountain Goats.

He had also collaborated on an Off Broadway musical, “Lazarus,” that was a surreal sequel to his definitive 1976 film role, “The Man Who Fell to Earth.”

Mr. Bowie wrote songs, above all, about being an outsider: an alien, a misfit, a sexual adventurer, a faraway astronaut. His music was always a mutable blend: rock, cabaret, jazz and what he called “plastic soul,” but it was suffused with genuine soul. He also captured the drama and longing of everyday life, enough to give him No.1 pop hits like “Let’s Dance.”

If he had an anthem, it was “Changes,” from his 1971 album “Hunky Dory,” which proclaimed:

“Turn and face the strange / Ch-ch-changes / Oh look out now you rock and rollers / Pretty soon now you’re gonna get older.”  © Leonhard Foeger/Reuters David Bowie performing at a concert in Vienna in 1996.

Mr. Bowie earned admiration and emulation across the musical spectrum: from rockers, balladeers, punks, hip-hop acts, creators of pop spectacles and even classical composers like Philip Glass, who based two symphonies on Mr. Bowie’s albums “Low” and “ ‘Heroes’.”

Mr. Bowie’s constant visual reinvention was a touchstone for performers like Madonna and Lady Gaga; his determination to stay contemporary introduced his fans to Philadelphia funk, Japanese fashion, German electronica and drum-and-bass dance music.

Nirvana chose to sing “The Man Who Sold the World,” the title song of Mr. Bowie’s 1970 album, in its brief set for the 1993 “MTV Unplugged in New York.”

“Under Pressure,” a collaboration with the glam-rock group Queen, supplied a bass line for the 1990 Vanilla Ice hit “Ice Ice Baby.”

Yet, throughout Mr. Bowie’s metamorphoses, he was always recognizable. His voice was widely imitated but always his own; his message was that there was always empathy beyond difference.

Born David Robert Jones on Jan. 8, 1947, Mr. Bowie constantly reinvented himself. He emerged in the late 1960s with the voice of a rock belter but with the sensibility of a cabaret singer, steeped in the dynamics of stage musicals. He was Major Tom, the lost astronaut in his career-making 1969 hit “Space Oddity.”

He was Ziggy Stardust, the otherworldly pop star at the center of his 1972 album “The Rise and Fall of Ziggy Stardust and the Spiders From Mars.”

He was the self-destructive Thin White Duke and the minimalist but heartfelt voice of the three albums he recorded in Berlin in the ‘70s, often considered his greatest work: “Low,” “ ‘Heroes’ ” and “Lodger.”

The arrival of MTV in the 1980s was the perfect complement to Mr. Bowie’s sense of theatricality and fashion. “Ashes to Ashes,” his sequel to “Space Oddity” that revealed “we know Major Tom’s a junkie,” and “Let’s Dance,” which offered, “Put on your red shoes and dance the blues,” gave him worldwide popularity.

Mr. Bowie was his generation’s standard-bearer for rock as theater: something constructed and inflated yet sincere in its artifice, saying more than naturalism could. With a voice that dipped down to baritone and leaped into falsetto, he was complexly androgynous, an explorer of human impulses that could not be quantified.

He also pushed the limits of “Fashion” and “Fame,” writing songs with those titles and also thinking deeply about the possibilities and strictures of pop renown.

Mr. Bowie was married for more than 20 years to the international model Iman, with whom he had a daughter, Alexandria Jones.

In a post on Twitter, the musician’s son from an earlier marriage, Duncan Jones, said, “Very sorry and sad to say it’s true. I’ll be offline for a while. Love to all.”

Mr. Bowie largely left the spotlight after a heart attack in 2004 brought to an abrupt end a tour supporting his album “Reality.” The singer experienced pain during a performance at a German festival and sought treatment for what he believed was a shoulder injury; doctors then discovered a blocked artery.

The following year, he performed with Arcade Fire, a band he had championed. In 2006, he performed three songs in public for what would be the final time, at the charity Keep a Child Alive’s Black Ball fund-raiser at the Hammerstein Ballroom in New York.