Complex sentence: In an effort to reproduce their success with "Bethlehem Down", he and Blunt proffered a new carol for Christmas 1929, "The Frostbound Wood"; technically accomplished, this failed to achieve the popularity of its predecessor.
Split into simpler sentences: In an effort to reproduce their success with "Bethlehem Down", he and Blunt proffered a new carol for Christmas 1929, "The Frostbound Wood". Although the work was technically accomplished, it failed to achieve the popularity of its predecessor.