With legendary rock icon Bob Dylan turning 70 today, and American Idol showing the final round of performances from its tenth season tonight, it's interesting to think of the ways that the singer and the show have intersected over the years. In many respects, you could consider Dylan and Idol to be polar opposites in their approach to American popular music. Dylan represents the purest example of the American singer/songwriter, writing his own music and lyrics, filtering the roots of the country's musical history (folk, country, even gospel) through his own personal style and worldview, creating templates for future generations of musicians to follow. By contrast, American Idol approaches the history of American music as one big popular songbook, to be regurgitated and occasionally re-interpreted but never added to or advanced, celebrating originality at times but mostly valuing the ability to conform to pre-existing pop ideals.

Yet despite this disparity, Dylan and his music have crossed paths with American Idol at several points throughout the show's ten-season run. Covers from contestants, comments from the judges, even a rumored gig on the show itself—the Rock and Roll Hall of Famer's presence has been felt on Idol more times than you might think. Here's a list of some of the more interesting examples of the overlap between the two fixtures of American popular music.

DYLAN SNEAKING ONTO IDOL IN DISGUISE. Back in 2008, Idol then-judge Paula Abdul made the bizarre claim to Ireland Online that not only was Bob Dylan a fan of the show, but that he had in fact attended two Idol tapings—with a fake beard so no one would recognize him. "[He] had a beard and tried to be in disguise," said Abdul. "But I knew it was him." The comment was written off as a testament to Paula's looniness, though given Dylan's recent history of playing with identity—a central theme to two Dylan-featuring '00s movies, Masked and Anonymous and I'm Not There—he wouldn't be the least likely rock legend to pull such a stunt.

JASON CASTRO'S "MR. TAMBOURINE MAN" FLUB. Bob Dylan makes for a tricky Idol cover for a number of reasons, one of the biggest being that most of his songs have a whole lot of lyrics—often trippy and/or radical ones—to remember. However, it's hard to imagine what Season  dreadlocked dreamboat Jason Castro's excuse was for forgetting the (fairly famous) chorus lyrics to "Mr. Tambourine Man" during his Top Four week performance of the Dylan original, as he mumured through the "In the jingle jangle morning / I'll come following you" lyrics at the song's outset. The judges seemed understandably confused and disappointed as to what has happened—except for Simon, who said simply: "Jason...I'd pack your suitcase." His prediction was on point, as Jason was eliminated the next night.

DYLAN'S RUMORED GUEST JUDGE STINT BEFORE SEASON FOUR. Buzz circulated in advance of American Idol's fourth season back in '04 that now that Paul McCartney was being recruited as a guest judge, Dylan wanted in as well. Entertainment Weekly reported that Dylan's "people" had even reached out to Idol producer Nigel Lythgoe to see if the rock legend's services would be desired. Whatever the truth of the rumors, and whatever they may have ended up amounting to, Dylan's stint on the show never materialized—and neither did Paul McCartney's, for that matter.

RANDY JACKSON PLAYING ON UNDER THE RED SKY. With judge Randy Jackson's proclivity for namedropping every single notable musician he's ever jammed with, shared a mutual friend with or exchanged passing glances with from across the room at a party, it's understandable that a collaboration with a rock legend such as Bob Dylan could get lost in the shuffle. But indeed, the one-time session musician did play on Dylan's Under the Red Sky album back in 1990, alternating bass work with the similarly prolific Don Was. We'd like to think we could tell the bassist's signature fretwork on the album, but we're not so sure, so you tell us if you can tell the fingerprints of the future Idol judge on this Dylan jam:

MELINDA DILLON'S DYLAN-REFERENCING ALBUM COVER. During her run on Idol's sixth season, Melinda Doolittle showed much more of an affection for classic R&B and showtunes with her song selections than she did for folk-rock. However, when it came time for her to release her first full-length studio album, Coming Back to You, she invoked the memory of Bob Dylan with the album's cover, whose framing and typography were clearly meant as an homage to Dylan's '62 classic LP The Freewheelin' Bob Dylan. Oddly, despite the cover, and despite the album consisting entirely of covers, no Dylan songs were found in the tracklisting.

SIMON'S DISPARAGING COMMENTS ABOUT DYLAN. One of the most frequently cited criticisms about the format of American Idol as an evaluator of musical talent is that it would have undoubtedly cast aside some of the more distinctive but less traditional voices of the rock era—like, say, Bob Dylan's nasally rasp. Perhaps sick of such comments, judge Simon Cowell lashed out against Dylan in a 2007 Playboy interview. "A singing poet? It just bores me to tears," claimed Simon. "I've got to tell you, if I had 10 Dylans in the final of 'American Idol,' we would not be getting 30 million viewers a week. I don't believe the Bob Dylans of this world would make 'American Idol' a better show."

KRIS ALLEN'S "MAKE YOU FEEL MY LOVE" RENDITION. The eventual Season Eight winner performed one of Dylan's most accessible numbers during Grand Ole Opry week, playing 1997's "Make You Feel My Love" without his signature guitar. "I thought that was terrific," testified a surprised-sounding Simon after the performance. "Probably the first time that I've actually heard you perform where I'm genuinely beginning to think that you've actually got a shot of doing really well in this competition." (Interestingly, Simon also repeatedly saluted Allen for his "smart choice of song," contradicting his previous comments on Dylan somewhat.) The song remained an Idol perennial, most recently being covered by New Orleans resident Sarah Sellers in a Season Ten audition—successfully, as the judges unanimously passed her to Hollywood.

Happy 70th birthday to Robert Zimmerman from all of us here at Popdust, and be sure to tune in for the final performance night of American Idol Season Ten at 8:00 EST tonight on FOX.