The EP used to be a viable way to release a handful of thematically linked songs that didn't fit well on an LP, but these days, while some EPs still fill that function, most are pitched with a different purpose. The Long Winters' Ultimatum (Barsuk) is a fairly typical new-breed EP, designed to showcase a single song indicative of an artist's new direction. That song would be "Ultimatum," which comes in live and studio versions. In both cases, it's a rousing, percussion-free ballad assembled from sloppy-fitting guitar-and-string runs, along with John Roderick's cut-vein bellow, "My arms miss you, my hands miss you"…

Meanwhile, the Iron & Wine/Calexico project In The Reins (Overcoat Recrodings) is a variation on that indie-rock standard, the split EP, where two bands contribute separate songs and cover each other's work. But In The Reins is actually a true collaboration, running Calexico's dusty southwestern twang beneath the humid whisper of Iron & Wine frontman Sam Beam. Beam has been moving toward fuller arrangements on his recent Iron & Wine records, so the brass hangings and rocking rhythms of something like "History Of Lovers" don't sound completely out of character, but what makes this generous seven-song set work is that both acts retain their individual strengths, filling up a room with sound, yet keeping the atmosphere intimate…

Similar (but different) is the Lambchop/ Hands Off Cuba EP CoLAB (Merge), in which the electronica/DJ group Hands Off Cuba remixes a few recent Lambchop songs and provides a backing track for a new Kurt Wagner composition, "Prepared." The remixes are generally pleasant and unexceptional, but "Prepared" is superior Lambchop, with Wagner's dry voice and drier character sketches rippling against the light waves of reverb and electronic redirection…

Robert Pollard's Music For 'Bubble' (Revolver USA) EP would come closest to serving the purpose of an old-fashioned EP, if it weren't really a soundtrack to Steven Soderbergh's new digital-video project, which makes its brevity mostly inadvertent. Still, Music For 'Bubble' is a consistent, entertaining piece of work, holding to a heavy classic-rock mode that both suits Pollard's sensibility and fits Soderbergh's characters, who work dead-end jobs at a doll factory…

Finally, there's Mark Eitzel's Candy Ass (Cooking Vinyl), a full-length album that probably should be an EP. Eitzel assembles spacey electronic instrumentals alongside more conventional folk-pop laments, and while the experimental tracks sound okay, they don't linger in the same way as the weaving, allegorical "My Pet Rat St. Michael," the hazy, regretful "Sleeping Beauty," and the sadly swinging cabaret number "Roll Away My Stone"—all of which stick to the classic Eitzel approach of breathy vocals and tinny guitars. Those three songs, with just a couple of their freeform brethren, would've made a heck of a mini.