Tortoise headlines The Ruins on June 25th. The Chicago group is, without contest, one of the most singular and influential acts of the '90s and early '00s. Key figureheads in what would loosely be called "post-rock," the instrumental collective freely blends (deep breath) jazz, modern composition, post-punk, dub, jungle, IDM, fusion, trip hop, progressive rock and much, much more into an aqueous, mercurial music that is as captivating as it is unique. Their discography is essential listening for all adventurous listeners, and their live show is simply breathtaking. Knockdown Center 21+