Ashlee Simpson-Wentz joined her sister to sing "Happy Xmas (War Is Over)" on her "Jessica Simpson: Happy Christmas" PBS special. The performance wasn't as bad as you'd think, but that's about it on the positive side. Ash, what's up with the hair? Not to mention that Jessica must be in one of her upswings... It's weird because I never would've thought it possible when Jess first came out, but Ashlee > Jessica vocally.