This guys are only three,but they sound incredible, Russian Circles with Carpe.

Russian Circles is a three piece instrumental rock/metal band from Chicago. Russian Circles play instrumental, sprawling music which runs the gamut of heavy discordant metal, to soft delicate passages. They are also known for their energetic live shows, which include tours withMinus the Bear, Chin Up Chin Up, Coheed & Cambria, Mono, and Pelican as well as an appearance at the 2006 SXSW.^[1] They were also the opening band for Tool while playing in theUnited Kingdom for their 2007 tour. Their name is taken from a drill exercise used in the game ofice hockey.
read more @ http://en.wikipedia.org/wiki/Russian_Circles

site http://russiancirclesband.com/
myspace http://www.myspace.com/russiancircles