I like Ethel's most recent release, which I downloaded from emusic.com but I'm at a loss as to how to describe the music to someone who has not already heard it since it's not my usual cup of tea and I find my vocabulary lacking. Tracks like Temporal Disturbances use voice samples to good effect, as well as percussive elements but it's mostly string-driven "classical" music with a modern interpretation. However, to put it squarely in the classical category isn't completely right. To me it seems to have elements of experimental music (all the wit and quirkiness with none of the randomness or atonality) and a sort of plucky rock / punk /pop sensibility, depending upon the tracks.
NPR has more information.
Edit 12/15: I've had more time with Light (still enjoying it) and I also downloaded Ethel's eponymous first release and can say with certainty that it is much less immediately accessible than Light. Ethel is to Light as la daube is to granita di limone - both satisfying, but in completely different ways. If you are curious about this group then start with their second release, Light.