R.E.M.'s In Time isn't called Greatest Hits, and for good reason: It serves not as an objective hits-roundup from the band's Warner Bros. years, but as a sometimes confounding overview of a catalog that can't be neatly summed up in 19 songs. Along with the requisite chart-toppers like "Everybody Hurts" and "Losing My Religion," In Time collects lesser-knowns like "At My Most Beautiful," from 1998's woefully underrated Up, and "The Sidewinder Sleeps Tonite," one of Automatic For The People's least appealing tracks. To further confuse, In Time adds a pair of new songs, including "Bad Day," which sounds like the more radio-friendly sibling of "It's The End Of The World As We Know It"–probably because the song, written and demoed in 1986, actually evolved into that early hit. The other new track, "Animal," wouldn't make sense on either a "best-of" or a "greatest-hits" collection. But those that do connect show why R.E.M. grew from a cultish college rock band into a Top 40 force: The aqueous beauty of "Nightswimming" remains potent 10 years on, and the crashing "What's The Frequency, Kenneth?" sounds even better removed from the largely unsuccessful Monster. Casual R.E.M. fans may mourn the lack of songs such as "Shiny Happy People"–the band successfully argued with its label to omit the track–but In Time doesn't seem to be aiming for them anyway, at least not squarely. Diehards should be pleased with In Time's two-disc option: Slightly pricier but well worth it, the set includes 15 B-sides, outtakes, and live versions, some of which rival the best material on the first disc. Of particular note is the dark, incredible "Fretless." Guitarist Peter Buck, in the set's casual but informative liner notes, even wonders why it didn't make the cut for 1991's Out Of Time. That mirrors In Time's only problem, which is a fine one to have: With so much worthy material, it's difficult to agree on the best.