Listening to Mark Kozelek attempt a full album of Modest Mouse covers is like watching a man wrestle a grizzly bear: It's a challenge that falls somewhere between courageous and stupid. Modest Mouse's music, more so than with many other bands, is nearly inseparable from the musicians themselves. Isaac Brock's spitting delivery determines the vocal melodies and his particular hardluck perspective determines his logic-puzzle lyrics. But his voice and words are only two gears in a much larger mechanism, and as such, for better or worse, they depend on the other cogs to turn them-- the rangey guitarwork that trails through the songs like sparks off a campfire, the staggering and surprisingly melodic basslines of Eric Judy, the strength and fluidity of Jeremiah Green's drumwork. They don't attempt many versions of others' songs, either; in fact, their only recorded cover to date is an instrumental-- Santo & Johnny's "Sleepwalk"-- to which they added dreamy vocals, nocturnal lyrics, and a descending arc of guitar notes to offset the moody original.