Bob Dylan was awarded the Nobel Prize in literature on Thursday for work that the Swedish Academy described as “having created new poetic expressions within the great American song tradition.”

He is the first American to win the prize since Toni Morrison in 1993, and a groundbreaking choice by the Nobel committee to select the first literature laureate whose career has primarily been as a musician.

Although long rumored as a contender for the prize, Dylan was far down the list of predicted winners, which included such renown writers as Haruki Murakami and Ngugi wa Thiong’o.

The permanent secretary of the Swedish Academy, Sara Danius, made the announcement in Stockholm. In a televised interview afterward, Danius said that Dylan “embodies the tradition. And for 54 years, he’s been at it, reinventing himself, creating a new identity.” She suggested that people unfamiliar with his work start with “Blonde on Blonde,” his album from 1966.

“Bob Dylan writes poetry for the ear,” she said. “But it’s perfectly fine to read his works as poetry.”

She drew parallels between Dylan’s work and poets as far back as Greek antiquity.

“It’s an extraordinary example of his brilliant way of rhyming and his pictorial thinking,” Danius said. “If you look back, far back, you discover Homer and Sappho, and they wrote poetic texts that were meant to be listened to. They were meant to be performed. It’s the same way with Bob Dylan. But we still read Homer and Sappho. He can be read and should be read. He is a great poet in the grand English tradition. I know the music, and I’ve started to appreciate him much more now. Today, I’m a lover of Bob Dylan.

Dylan will receive an 18-karat gold medal and a check for about $925,000.

Tributes for Dylan — as well as the Nobel’s unconventional choice — came from across the world and spanned from the worlds of politics to letters.

“Dylan is the brilliant inheritor of the bardic tradition. Great choice,” said a Twitter message from British novelist Salman Rushdie. Chile’s president, Michelle Bachelet, called the honor for Dylan a “joy” and recalled “many fond memories from my adolescence are associated with his music.”

Just after 7 a.m., songwriter Rosanne Cash was in her New York home when her husband John ran down the stairs “like an elephant.”

“Dylan won the Nobel Prize,” he shouted.

“No,” said Cash, “that can’t be true.”

Cash, whose legendary late father, Johnny, was a friend and sometime collaborator with Dylan, spent the rest of the morning beaming. She also received a flurry of text messages, everyone from songwriter Marc Cohn to her literary agent.

“The chatter is this pride and that finally he gets recognized in this way that equates songwriting with great literature,” said Cash. “I can’t tell you how many times people have said to me, because I also write prose, ‘Oh, you’re also a real writer.’ It’s so offensive. Like songwriting doesn’t require the same discipline. So the fact that he’s recognized lifts all of our boats.”

But at last one prominent writer, however, took issue with the Nobel selection. Scottish novelist Irvine Welsh, author of “Trainspotting,” decried it as “an ill-conceived nostalgia award” made for “senile, gibbering hippies.”

Dylan, the son of a Minnesota appliance-store owner, began as a folk singer but soon established himself as one of the voices of political protest and cultural reshaping in the 1960s.

Dylan’s songs — driven by his distinctive nasal-twang vocals — are often seen as dense prose poems packed with flamboyant, surreal images. Rolling Stone magazine once called him “the most influential American musician rock and roll has ever produced.”

He first gained notice with ringing protest songs that served as anthems for the civil rights and anti-Vietnam War movements with such songs as “Masters of War,” “The Times They Are a-Changin’,” and “A Hard Rain’s a-Gonna Fall.”

Then he moved on to feverish rock-and-roll drenched in stream-of-consciousness lyrics that evoked the hallucinatory visions of William Blake, the romanticism of Mary Shelley and John Keats and the postmodern pessimism of Allen Ginsberg and other beat poets.

Dylan recalled listening to country music each evening from distant Midwestern stations and taking up the guitar himself at age 10.

He briefly attended the University of Minnesota in Minneapolis, where folk music, rather than rock-and-roll, was the abiding musical idiom.

“Picasso had fractured the art world and cracked it wide open,” Dylan once wrote. “He was revolutionary. I wanted to be like that.”

Dylan was described in an ad for his 1962 Columbia Records debut as “a major new figure in American folk music.” As it turned out, the marketing hyperbole sold him short: Dylan revolutionized popular music and became a major cultural force.

Dylan sang at the 1963 March on Washington, the massive civil rights procession presided over by the Rev. Martin Luther King Jr. Later, at the 1965 Newport Folk Festival, he stunned many fans — and began a new musical direction — by putting aside his acoustic guitar and playing a Fender sunburst Stratocaster electric guitar.

His next albums — “Highway 61 Revisited” and “Blonde on Blonde” — ventured further into the surreal long-form songs and dizzying array of characters that were becoming his trademark. They are considered by many critics to be his creative peak.

When he was in the Los Angeles-formed band The Byrds, Roger McGuinn sang enough Dylan covers to fill two albums, including the band’s chart-topping, 1965 version of “Mr. Tambourine Man.” Later, he toured with Dylan and played his 12-string Rickenbacker guitar on Dylan’s 1973 hit “Knockin’ On Heaven’s Door.”

“I always thought working with him was like knowing Shakespeare,” said McGuinn. “Mr. Tambourine Man. The imagery of that. ‘Yes, to dance beneath the diamond sky with one hand waving free/ Silhouetted by the sea, circled by the circus sands.’ It’s beautiful and really poetry.”

In the late 1970s, he stunned admirers again by declaring himself a Christian and releasing three albums of religiously inspired songs. The singing and musicianship were passionate and professional — Dylan earned his first Grammy Award, for best rock male vocal performance — but the harsh, born-again lyrics puzzled and alienated many of his longtime fans.

Musician Peter Case was a kid growing up in Buffalo when his mother brought him a copy of Dylan’s latest record, the 1965 album, “Bringing It All Back Home.”

“It opened me up to Shakespeare and the sound of language and to try to understand it,” says Case, 62. “It opened me up to deep compassion about people.”

“He’s just a giant,” he added. “They had to open a special door for him.”

In 2005, Dylan released a long-awaited memoir, “Chronicles Vol. 1,” which won him more accolades for its candor and originality. He also appeared in director Martin Scorsese’s “No Direction Home,” a documentary that summed up the triumphs and turmoil of his early years as a performer. In 2008, he was awarded a special Pulitzer Prize for his profound effect on popular music and American culture, “marked by lyrical compositions of extraordinary poetic power.”

In February 2010, Dylan took the stage at the White House for a concert honoring the music from the 1960s Civil Rights movement. Backed by only a piano, he performed a powerful acoustic rendition of “The Times They Are a-Changin’” as President Obama watched from the front row. Dylan then shook Obama’s hand in their first meeting.

“As composer, interpreter, most of all as lyricist, Dylan has made a revolution,” the late New Yorker critic Ellen Willis once wrote. “He expanded folk idiom into a rich, figurative language, grafted literary and philosophical subtleties onto the protest song, revitalized folk vision by rejecting proletarian and ethnic sentimentality, then all but destroyed pure folk as a contemporary form by merging it with pop.”

Dylan, Willis noted, “imposed his . . . literacy on an illiterate music.”

“Things were changing all the time and a certain song needed to be written,” Dylan said in 1965. “I started writing them because I wanted to sing them. . . . One thing led to another and I just kept on writing my own songs.”

He added that “popular songs are the only art form that describes the temper of the times. . . . That’s where people hang at. It’s not in books. It’s not onstage. It’s not in the galleries.”

“The way Elvis freed your body, Bob freed your mind and showed us that just because the music was innately physical did not mean that it was anti-intellectual,” Bruce Springsteen said upon inducting Dylan into the Rock and Roll Hall of Fame in 1988.