On
Ball,
Iron Butterfly began to expand its sound, attempting to write more concisely. On
Metamorphosis, the group continued its musical explorations, adding a layered production to its sound. This ambition, highlighted by a handful of strong tracks, particularly the single "Easy Rider (Let the Wind Pay the Way)," makes for an interesting listen, since
Iron Butterfly's albums can be weighed down by their relentless heaviness. ~ Stephen Thomas Erlewine