With an eclectic all-instrumental blend of rock, jazz, dub, electronics, and the avant-garde, Tortoise emerged as the leading band of Chicago’s so-called “post-rock” scene in the 1990s. On its seventh album The Catastrophist, the group has introduced a radical new element: vocals. Tortoise joins hosts Jim DeRogatis and Greg Kot for a conversation and performance. Jim and Greg also explore the history and legacy of the post-rock movement. Plus, a tribute to Alan Vega of Suicide and a review of the new album from British soul musician Michael Kiwanuka.