Few rock historians would call Bill Haley's "Rock Around the Clock" the first rock and roll song. (Many would give that honor to Jackie Brenston's 1951 "Rocket 88," co-written by Ike Turner, produced by Sam Phillips, and later covered by Haley.) When asked to date the beginning of the rock and roll era in popular culture, though, it's hard to peg a more precise date than March 19, 1955: the day the movie Blackboard Jungle opened, with "Rock Around the Clock" blaring over the opening credits.

Preceded by an ominous drum-solo introduction while a crawl of text warns viewers that they're about to see a cautionary tale, Haley's now-legendary count-off ("One, two, three o'clock, four o'clock, rock!") begins as the movie's title flashes on a literal blackboard; after the film's brief opening credits are complete, the song fades back to become source music as a schoolteacher played by Glenn Ford arrives at a school for male juvenile delinquents. In the school's bleak courtyard the boys sneer at Ford, even as some dance to the music: it helps to mark their territory.

For many viewers, with that scene it all fell into place: a musical revolution that had been brewing for years suddenly came into sharp focus. Haley's song sounded like a manifesto, with its repeated incantation of the word "rock." That term, which derived from randy R&B songs, had been incorporated into the term "rock and roll" - coined by DJ Alan Freed in the early 50s to describe the new hybrid of R&B, country, and swing.

If "Rock Around the Clock" sounds more than a little quaint by today's standards, consider how edgy it would have sounded among the other chart-toppers of 1955: "Mr. Sandman," "The Ballad of Davy Crockett," "Autumn Leaves," "The Yellow Rose of Texas." In Haley's breezy delivery, "rock" became abstracted: as a verb, "rocking" could encompass not just dancing or canoodling, but an entire lifestyle. The McGuire Sisters did not rock; the kids in Blackboard Jungle did.

Haley's single had actually been released the previous year, but had stalled on the charts; buoyed by its use in the movie, "Rock Around the Clock" went to number one and stayed there for weeks. As years, then decades, went by and it became obvious that rock and roll was, in fact, here to stay, it became increasingly clear that Blackboard Jungle and "Rock Around the Clock" had marked a turning point in popular culture, the moment when rock and roll went from being a musical niche to a wide-ranging cultural phenomenon that could never again be ignored.

Though Blackboard Jungle remains passably well-regarded as a movie, it's now best-known for its role in the rock and roll revolution. It played that role to a T, and not just in its credits. Director Richard Brooks's adaptation of Evan Hunter's 1954 novel was sufficiently hard-edged that it needed substantial cuts to be shown in the U.K.; on both sides of the Atlantic, it was a hit among teenagers, with screenings sometimes marked by outbreaks of violence among kids who were excited by the snarlingly irreverent boys depicted onscreen. As stories of the teen "riots" at Blackboard Jungle screenings spread while "Rock Around the Clock" blared on radios, rock and roll's association with youthful rebellion was forever sealed.

Watching the film today, it's easy to pick out other elements that became core to the newborn rock and roll mythology. The setting is explicitly urban, helping to identify rock and roll as city music; while its parents might have come from a Kentucky barn dance and a Mississippi juke joint, rock and roll would be recorded, amplified, and blasted in the concrete canyons of the inner city.

In one scene, there's even a ceremonial smashing of jazz records belonging to a harangued teacher. Symbolically, the scene could be read as marking the end of an era in which jazz was the "hot," scandalous urban soundtrack. As rock and roll gained momentum while a generation of innovators pushed jazz into new sonic territory, jazz became increasingly regarded as high art instead of popular entertainment: the province of aesthetes instead of the streets.

Most significantly, Blackboard Jungle put race relations at its core. Ford's class is racially and ethnically diverse, and he rebukes the kids for their casual use of ethnic slurs—only to then be accused himself of racism, a charge that he accidentally reveals in a heated moment might be more true than he'd like to admit. Nonetheless, Ford slowly wins the confidence of a black student played by a young Sidney Poitier, who is seen leading other African-American students in a gospel vocal group of the kind that had enthralled Elvis Presley—the white Mississippi boy who would emerge a year later as rock and roll's first superstar.

The fact that it was Blackboard Jungle that launched Haley's single—and rock and roll generally—into the stratosphere also cemented the enduring relationship between rock and roll and motion pictures. Though the first "talkie" was about a jazz singer, rock and roll was the first great music genre that was truly native to the silver screen. From Blackboard Jungle to Easy Rider to Pulp Fiction to The Hunger Games, rock music has always been closely associated with the movies.

It seems especially apt that when "Rock Around the Clock" became the first rock song ever to be used in a Hollywood movie, it wasn't depicted as being performed live: the film's opening scene suggests that the kids are listening to the song on the radio, helping to define recorded sound as the fundamental medium of rock and roll. Whereas classical music and jazz were born in eras when live performance was still the primary means by which people heard music, rock and roll would forever be about the record: most rock fans, then and now, heard the record first and only later, if ever, heard the music performed live.

Blackboard Jungle is available to rent on iTunes and Amazon, and it's well-worth watching as it celebrates its 60th birthday today. Its raucous reception didn't mark the birth of rock and roll, but when Blackboard Jungle hit theaters, the whole world started to rock—and it still hasn't stopped.

https://www.youtube.com/watch?v=dKZcHwiv0E4