With the long-awaited release of the Led Zeppelin catalogue for on-demand play, we?re still wrapping our head around the size of the band?s shadow--and the fact that it continues to grow. We asked Spin/Rolling Stone/Blender editors and writers Craig Marks and Rob Tannenbaum to discuss, and they invited Ann Wilson of Heart, Wayne Coyne of Flaming Lips, famed Zeppelin photographer Neal Preston, and Jon Wurster of Superchunk to join the conversation.