The same people who would label True Aristocrats' music as "prog" would probably think the same thing of Naked City or Mr. Bungle. Not that the Aristocrats (due at Road 34 in Fort Collins on Saturday, December 10) sound anything like either of those two projects, but a vibrant spirit of experimentation and boundary-pushing is very much in place. If the band's debut full-length — the aptly titled Susurrus, issued earlier this year — is any indication, the duo (often a trio live) is capable of improv-rock freakouts as well as abstract meditations on a mood, sometimes within the same song. Even a cursory glance at what the group has written about itself reveals a far-better-than-average level of intelligence, but it's the music that deserves more than a casual listen.