It was a night of throwbacks on "American Idol," as the show hit a theme it last visited during season seven, exploring the legendary songbook of Beatles greats John Lennon and Paul McCartney. So how did the 2010 "Idol"-ers fare during the evening's homage to the musical past? Casey James brought the smoldering soul, Crystal Bowersox and Lee Dewyze hauled out some atypical instruments, and Aaron Kelly nearly put the audience to sleep when the "Idol" show was but minutes old.

Yes, Kelly kicked off the show with "The Long and Winding Road," a mournful tune from Let It Be and yet another ballad for the teen. During his introductory video, we found out that his cohorts have dubbed him Yoda, but there was nothing wise about this dull performance. It was lacking in energy and the steady vocals he's displayed in recent weeks.

Randy Jackson nailed it when he called the rendition "sleepy," as did Ellen DeGeneres when she renamed his version "The Long and Winding Song." But Simon Cowell summed up Kelly's by-now-tiresome predictability best when he said, "You've got to become young and relevant. ... You're doing the same thing week after week. You've got to have a moment and take some risks."

Back in '08, Brooke White delivered a piano-driven, goose-bump-inducing take on "Let It Be." When it came to "Idol" comparisons — not to mention the contrast to the Beatles' original or Kris Allen's take earlier this year — a hot-pink-outfitted Katie Stevens had a lot to live up to. Though it didn't reach the heights of those examples, it was a perfectly fine performance, even if it did have a distinct teen-recital air to it.

The judges didn't seem to mind or notice. All agreed that Stevens had found her form again after floundering for a few weeks, though they didn't agree on the reasons why. Simon feted what he believed to be a country vibe to the tune, while Kara and the rest of the crew couldn't have disagreed more. But no matter! With both ends of the judges' table in agreement that she rocked, Stevens might well avoid ending up in the bottom three for a third straight week.

Coming off a comeback performance during R&B week, Andrew Garcia and his acoustic guitar opted for a horn-assisted take on the 1964 #1 hit "Can't Buy Me Love." The arrangement seemed to morph the house band into a garage-band version of the Mighty Mighty Bosstones, which then swallowed much of what Garcia was trying to contribute. No doubt, it was a regression for the guy.

While Ellen loved it, Kara admitted with a shrug, "Aw, I wanted to love it, I do." Her complaint, as well as Simon's, was that Garcia has yet to show off a different side of himself. The subtext to that assessment, of course, is that the 24-year-old has yet to bust out a song as memorable as his reworking of "Straight Up" during Hollywood Week. And where was Andrew's mom? Mrs. Garcia, we miss you!

Season-seven champ David Cook pulled off a goth-tinged rendition of Revolver's "Eleanor Rigby" that wowed judges and voters alike in '08. Variously described by his fellow contestants as a teddy bear, the Incredible Hulk and an insanely loud snorer, Big Mike Lynche took a huge risk with the same tune — and it mostly worked. In terms of the arrangement, the staccato strings ended up obstructing the overall flow of the song, but Mike's vocals were on point and he earned bonus points for a courageous refashioning of a classic tune. Just like Cook, come to think of it.

Ellen got it right when she said there are many intriguing sides to Lynche. Kara used words like "fire" and "drama" to pinpoint the highs of the theatrical rendition. Simon alone found the whole thing a bit too musical for his tastes, even if he did take time to pay lip service to Fox's hit musical show "Glee."

Crystal Bowersox — who shall henceforth be known as MamaSox, per her introductory video — was fighting off both a cold and an arrangement that just was not working at all. Her vocals during Abbey Road's "Come Together," soulful as ever, fought for breathing room among the fat bass line, the electric guitar and ... the didgeridoo? Still, MamaSox always keeps it interesting, which is why she remains the most consistently compelling contestant of season nine.

Does it matter that, as Randy noted, it wasn't close to her best performance of the season? Probably not, because it was still memorable. Do we entirely agree with Kara, who gushed about MamaSox's slinky sexiness during the song or Simon, who said, "That's a performance I could hear on the radio"? That, too, is beside the point. Crystal is at the head of the "Idol" class for a reason.

And then we came to "Teflon" Tim Urban. If you didn't know it before, you knew it after his pre-performance video: The guy likes to smile. Sticking with that upbeat sensibility, Urban chose "All My Loving," from 1963's With the Beatles. It veered from solo guitar quietness to full-band '50s rock swing, but at every turn his vocals actually held steady.

Randy didn't seem to know what to say, declaring his intention to judge Urban in terms of a "Tim performance," by which metric the singer did well. Ellen compared him to a shaggy-haired Paul McCartney. An almost apologetic Kara encouraged him to smile after a well-done performance. Refusing the impulse to condescend to the contestant, Simon said, "I thought you did really well with that song."

One of Casey "Goldilocks" James' strongest performances to date was his acoustic take on Bryan Adam's "Heaven." On Tuesday (April 6), he returned to that stripped-down style with a bold rearrangement of Lennon's 1971 tune "Jealous Guy," bringing a soulful growl to the proceedings.

Randy and Kara liked that James showed off his authentically sensitive side, while Ellen decided this was Casey's finest performance to date. Simon went a step further than Ellen, declaring Casey's "Jealous Guy" the best performance of any contestant the entire night.

In terms of music, Siobhan Magnus might have been riffing on the Beatles with "Across the Universe," but her outfit — that punky wedding-dress conglomeration — was a none-too-subtle nod to Madonna in her "Like a Virgin" days. The song itself felt a little like the work of a Disney-imagined fairy godmother, even if it sounded delicately melodious.

None of the judges could suggest anything other than that Magnus is a true original. They variously called her special, crazy and unpredictable, though Kara questioned a newfound politeness she saw in the singer. Said Randy, "No one screams 'artist' more than you." Siobhan's tearful, post-song speech about her younger sisters may have bored Simon, but it likely tugged the heartstrings of the voting public.

Wrapping up Lennon/McCartney week was Mr. Lee Dewyze, who hauled out a kilt-wearing bagpiper for his rendition of the 1968 hit single "Hey Jude." Ditching the success he had with a full band last week, he decided to indulge his singer/songwriter impulses with a largely acoustic performance. After an initial faulty note, his vocals were, for the most part, tight, and he continued to improve his onstage presence.

The judges were left cracking up over the bagpipe player — but only Simon was laughing at Dewyze rather than with him. "It was like he turned up on the wrong show," Simon said, before ending the night with a query we might have liked to ask many of the contestants: "Was it your idea?"

What did you think of tonight's "Idol" performances? Who was your favorite? Let us know in the comments below!

Get your "Idol" fix on MTV News' "American Idol" page, where you'll find all the latest news, interviews and opinions.