When the members of Fall Out Boy were recording 2007's Infinity On High , they turned to two albums for guidance. One was a late-'90s hardcore record from Sweden. The other was Michael Jackson's Thriller . "It's the best pop record ever," frontman Patrick Stump said at the time. "It's mindless catchiness with the most mind to it."

At first, the lustrous post-disco sound of Thriller seems an unlikely muse for Stump and his bandmates: When Fall Out Boy covered Jackson's "Beat It" a few years ago, their punky homage had more in common with Queens of the Stone Age than it did with the King of Pop. In fact, while numerous rockers have paid homage to Jackson via cover song — including Chris Cornell, Alien Ant Farm, and Death Cab for Cutie's Ben Gibbard — few of them have any discernible musical connections with the Gloved One. After all, Jackson's sound — with its quivering vocals and trademark whooos and hee-hee s — made for tricky dittoing. And yet Thriller , despite not technically being a rock & roll album, has had a bigger impact on rock & roll than just about any other album of the past 30 years. It's just not always easy to hear it.

For starters, consider Jackson's nearly cyclopean musical ambitions, which were obvious to anyone who unwrapped Thriller for the first time and heard the six-minute opener, "Wanna Be Startin' Something," which begins with an almost compulsory dance beat and ends with an African chant. It was anthemic, and unapologetically so. The success of Thriller was not some happy accident; it was the result of countless hours of in-studio calculation and calibration, all in the name of maximum appeal. " Thriller was geared exclusively toward making the best singles," Stump noted. "Michael Jackson and Quincy Jones said, 'We have to make pop music better.' "

Of course, if there were ever a DSM-IV diagnosis for pop stars, that sort of stratospheric hubris would be symptom No. 1, and certainly, Jackson wasn't the first musician consumed with dominating the charts. But when Thriller was released in 1982, the over-the-top moxie that had come to define pop music was falling out of favor: Punk had exposed the tacky vanities of Led Zeppelin and Aerosmith, while disco had tipsily staggered back underground. The sort of world-ascension moxie that had ruled the '70s was in temporary decline, which made Thriller all the more jarring. Jackson provided aspiring pop and rock stars everywhere with a sort of mission-statement-slash-permission slip, one that allowed them to be as sleek and audacious and as they wanted, so long as the music was perfect. Pink Floyd's The Wall might get all the credit for being the seminal '80s concept album, but to the millions of teens and pre-teen Jackson fans who grew up listening to Jackson — some of whom went on become musicians — no musical statement could ever be as grand or intimidating as Thriller .

Jackson's other major contribution to rock music comes with an exact timestamp: Thriller , side two, at the 2:49 mark, when Eddie Van Halen interrupts "Beat It" with a boiling 31-second guitar solo. Even in the wake of Jimi Hendrix or Sly and the Family Stone, black artists were impossible to find on rock radio in the early '80s, but the clamor for "Beat It" forced even the most stubborn DJs — and well as MTV programmers — to desegregate their playlists. "At that time in my life, I wasn't really a fan of Michael's music," says Cornell, who was living as a teenager in Seattle when he first heard "Beat It." "But [ Thriller ] had a big impression for me. It opened the door for Prince and Run-DMC to suddenly be in the living rooms of white people across the nation."

It also primed listeners for the slew of genre-mingling Top 40 hits that followed: Prince's "Let's Go Crazy." Run-DMC's "King of Rock." Living Colour's "Glamour Boys." Even Jackson's own "Dirty Diana." Most of these songs would have come to prominence without "Beat It," of course, as would the numerous black-rock bands like Fishbone and 24-7 Spyz that would become breakout college-radio acts later on in the decade. But the crossover success of "Beat It" subtly made a point that Jackson would repeat, rather pedantically, nearly 10 years later: It doesn't matter if you're black or white. Not everyone got the message, but those who did discovered an entire new framework for how pop, rock and R&B can merge.

In the end, Jackson's influence on rock & roll will always be more cultural than musical; it's not as though you can go to the Warped Tour or turn on Fuse and come across a bunch of Thriller sound-alikes. Yet for anyone making music now or in the future, Jackson's best moments will always be throbbing somewhere in the background — an undeniable, unavoidable force.

"It's impossible to say, musically, where I may have been influenced by Michael Jackson," admits Cornell. "Because I didn't buy his records and listen to 'em. [But] I think that an artist whose music is on television, and constantly coming out of radios and speakers in people's cars, and just sort of permeating pop culture, there's no way you could say that you weren't in some way influenced by it."