After the departure of three founding members, Robert Fripp and Peter Sinfield assumed expanded roles for In the Wake of Poseidon. In the snarling proto-punk assault of “Pictures of a City,” King Crimson foreshadows grunge, but they are quick to balance the mood with “Cadence and Cascade,” a sliver acoustic folk as seamless as a glass vase. “The Devil’s Triangle” is the album’s intricate centerpiece. Listeners who venture through its cloudbank of mellotron and strings are rewarded with a finale of eruptive psychedelia.