As the sixth domestic Aerosmith hits collection and the first to feature selections from both their Columbia and Geffen years (not to mention that it's the second double-disc retrospective released within eight months), The Ultimate Aerosmith Hits should live up to its title -- and it does, for the most part. Over the course of two discs and 30 songs, almost all the heavy-hitters are hauled out, from "Mama Kin" to "Jaded," including both versions of "Walk This Way." Some of the songs are presented in a remixed form -- "Draw the Line," "Pink," "Just Push Play" -- but all of the new mixes are good, possibly even improvements, and the new song, "Girls of Summer," is strong (its companion, "Lay It Down," isn't as noteworthy). So, all the parts are in place -- why doesn't it feel definitive, then? After all, there are no big songs or hits missing (apart from the cover of "Come Together," which isn't much of a loss), just fan favorites and album tracks like "Lord of the Thighs," "Lick and a Promise," and "Chip Away the Stone" (and nothing from Done With Mirrors, for that matter). The reason it doesn't feel definitive is that the classic Columbia recordings are wrapped up by track ten, and then the best of their late-'80s comeback is wrapped up by the end of the first disc, which leaves disc two pretty much devoted to everything from Get a Grip on -- an era not widely considered their best, even though it had a number of hits, plus a couple of good songs along the way ("Crying," "Deuces Are Wild"). So, even though this delivers everything it should and will certainly be the one Aerosmith disc most casual listeners will need, it doesn't quite capture the essence of the band the way their greatest albums do (whether they're Rocks or Pump).