“Ice Ice Gravy” might only be a single track that cobbles together some outtakes from the recording sessions for Tortoise’s most recent album, 2009’s Beacons of Ancestorship, but it pretty much captures the Chicago collective in a nutshell. The jazz-rock hybrids, the space-age bachelor-pad atmospherics, the spaghetti-western lite noodlings—they’re all here, and they go to show how imprecise the shorthand term “post-rock” really is.

Built from the fits and starts that the band went through in the process of making Beacons, the 13-minute sound collage covers many of the styles and moods for which Tortoise is known.  However, the strung-together odds and ends could use smoother transitions and more seamless than fade-outs, because about halfway through the track, “Ice Ice Gravy” begins to resemble a playlist of 30-second iTunes samples. At their best, the fragments seem like the makings of what could have become some pretty strong songs, but by now Tortoise has figured out how to tell which brainstorming improvisations only yield false starts, and that is what “Ice Ice Gravy” ultimately sounds like.