Many video game industry analysts proclaim that the rhythm genre peaked by mid-2009. But its latest releases, “Guitar Hero 5” and “Rock Band: The Beatles,” continue to raise the quality of plastic instrument games through dynamic tweaks to their game play and presentation. So don't go smashing that Les Paul controller over your coffee table just yet.

Some players claim a rhythm title is only as good as its set list, and Activision's “Guitar Hero 5” scored several heavyweight tracks to support its staying power on game shelves. Nirvana's “Smells Like Teen Spirit” and Queen and David Bowie's “Under Pressure” stand out among 85 songs spanning new and old, indie and classic, and all are immediately playable at the start of the game.

Where “Guitar Hero 5” handily surpasses past rhythm games is its accessibility. The “Party Play” mode permits ensembles of four guitarists or drummers instead of the traditional band setup of guitarist, bassist, singer and drummer (which sometimes results in a boring time for the bassist). Players can also swap difficulties or simply stop mid-song without disturbing the experience for bandmates.

These changes to the game directly address the biggest barriers to fun posed by the genre in the past. In previous rhythm games, when a player was caught off-guard by a challenging part in the song, they would fail, halt progress for the rest of the band and possibly sap its tally of points or fans. The removal of the imperative to succeed relaxes the game play for everyone and keeps an easy-going atmosphere from filling with frustration.

Meanwhile, challenges and “RockFest” modes complement the accessibility of “Party Play” with several types of more achievement-oriented competitive play. By giving players venues to score points and win contests with perfect playthroughs, “Guitar Hero 5” also shores up its appeal to the crowd that prizes mastery of rhythm game play.

The mechanical improvements “Guitar Hero 5” makes to the rhythm game formula are more than matched by the fan-service polish EA applies to it with “Rock Band: The Beatles.”

Whereas band-specific editions of “Guitar Hero” have also widened their scope with songs by said band's influences, peers and descendants, “Beatles” contains nothing not performed by the Fab Four. Players can enjoy 45 songs spanning the group's near-decade of cultural and critical conquest, from “Boys” to “Get Back.” The slightly less steep difficulty of “Beatles” compared to “Guitar Hero 5,” combined with the songs' average three-minute length, makes each playing experience a fun burst where fatigue is no threat.

With a body of work as brimming with unmistakable hits as The Beatles', critiques of the set list can ensue endlessly. There's no “Strawberry Fields Forever” and no “Eleanor Rigby,” for example. The general brevity of the set list may attract additional ire. (Players can download full Beatles albums, such as “Abbey Road” and “Sgt. Pepper's Lonely Hearts Club Band,” for additional fees).

But if there was ever a case of quality trumping quantity, particularly in rhythm games, it's in “The Beatles: Rock Band.” Each amazing song's accompanying video is attentively sculpted to augment the experience of playing it. Through the game's story mode, players progress through the most iconic scenes of The Beatles' career: “The Ed Sullivan Show,” Shea Stadium and the final performance above the Apple HQ rooftop, for example.

Perhaps the most enjoyable videos are the more dreamlike fugues for the band's latter-career music. “I Am the Walrus” incorporates the silly animal masks the band originally wore in the song's “Magical Mystery Tour” music video, “Octopus' Garden” plunges the band to the ocean floor and “Helter Skelter” blitzes the screen with staticy animation to accent the song's sonic chaos.

Unlike the sight of Kurt Cobain belting Bon Jovi in “Guitar Hero 5,” players can't enjoy the anachronism of mixing and matching the Beatles' early songs to late-career settings and vice versa. This devotion to authenticity manifests in more disappointing and simply dry aspects to the game, such as the lack of drum fills and the abrupt cutting out of music when a song is failed.

Those are the only weaknesses of an otherwise lovingly crafted title that's bolstered by little touches like unlockable rare photos and in-studio dialogue before each song begins. The introduction of vocal harmonies (a strong addition that compounds the cooperative fun and challenge of playing) for “Beatles,” as well as the game's unique psychedelic fretboard animations and menus, also speaks to designer Harmonix's wholly reverent attitude toward the band.

This attitude - call it Beatlemania, just as Harmonix renamed its “Overdrive” feature - is certainly contagious in the newest “Rock Band,” and illustrates why the rhythm game genre is getting better all the time.

If you play.

Game: “Guitar Hero 5”

Score: A

Parental rating: Teen for mild lyrics and suggestive themes

Developer: Neversoft

Publisher: Activision

Platform: PlayStation 3, Xbox 360 (also available for Wii and PlayStation 2)

Price: $59.99

Play: Single, multiplayer

The final boss: “Guitar Hero 5” simultaneously widens its appeal to less-serious players while giving the experts several new ways to challenge themselves.

Game: “Rock Band: The Beatles”

Score: A+

Parental rating: Teen for mild lyrics and tobacco reference

Developer: Harmonix

Publisher: EA

Platform: PlayStation 3, Xbox 360, Wii

Price: $59.99

Play: Single, multiplayer

The final boss: The greatest band of all time gets red-carpet rhythm game treatment in “Rock Band: The Beatles,” and the result will likely win them new fans while reminding long-standing ones why they fell for the Fab Four.