Having set the electric guitar aside in favor of keyboards, mellotrons and kitschy noise machines, guitarist Peter Buck and bassist Mike Mills traded job descriptions for Up, playing each other's instruments in addition to a host of other rhythm machines and analog synthesizers from Buck's private collection.

The first listen to Up is likely to incite a few raised eyebrows and dropped jaws. Aside from Stipe's trademark vocals, it’s not always easy to believe that the music underneath is being played by R.E.M.

In fact, the album begins with the band's most experimental offering to date, as the low gurgles of "Airport Man" fizz, pop and crackle into an eerie coagulation of soft vocals and vibrating keyboards.

Following suit to 1996's New Adventures in Hi-Fi and 1995's Monster, the second track of Up proves to be the album's real jumpstarter. "Lotus" kicks off with a raspy "Hey, hey!" chant and a dazzling roller-rink keyboard intro, ultimately stepping into a swaggering chorus. A vintage guitar riff rattles around the verses, recalling the warped and jagged edginess of 1985's Fables of the Reconstruction.

For all its weirdness, parts of Up bear similarities to many other R.E.M. albums. The mandolin sections on "You're In The Air" could just have easily fit on Out of Time, while the darker aura of "Sad Professor" and "The Apologist" would not be terribly out of place on Automatic For The People.

Thanks to Stipe's ease with channeling his emotions in a third-person voice, Up is another "character record," much like Fables of the Reconstruction. But where the subject matter of Fables’ songs came from actual fixtures of Stipe's Athens neighborhood, the characters on Up are mostly creations of Stipe's imagination.

The protagonist of "Hope" struggles with the decision of whether to trust science or religion, while the elderly gentleman in "Sad Professor" finally comes to grips with his inability to get through to his students. A courtroom drama unfolds in the spooky bass-driven "Diminished," while a moment of epiphany bursts open for the subject of "Walk Unafraid," - Stipe's favorite album track - which was lyrically inspired by Patti Smith.

The album's lone love song is perhaps the best track on Up, with some of the most romantic imagery ever to grace an R.E.M. album. "I count your eyelashes secretly / with every one whisper I love you," croons Stipe in the Beach Boys-esque "At My Most Beautiful." With multi-part background harmonies and an orchestral swirl of strings and piano, this is clearly the best song Brian Wilson never wrote.

Much like OK Computer, Up works best when the drips and churps of the added instrumentation enhance the melody instead of drown it out. The frazzled synthesizer on "Suspicion" fills out its subtle background, eliciting one of Stipe's most gorgeous melodies in recent memory. First single "Daysleeper" benefits from a few wisps of feedback and remains the album's most traditionally structured R.E.M. song. Here, Stipe discusses the dangers of technology and its effects on a night worker whose stressful nights have been colored "headache grey" with responsibility. The song's infectious minor-keyed chorus proves R.E.M. is still more than capable of appealing to a mass audience.

In the band’s tradition of strong album closers, “Falls To Climb,” the closing salvo of Up, is a chilling session of self-introspection. Light-years from “Radio Free Europe” but still perfectly essential, Mills' soft organ and Buck's acoustic guitar melt with Stipe's powerful and uplifting chorus to unearth the track’s quintessential R.E.M. feel.