What are you, strolling through the Prog Hall Of Fame?!?!?
FYI, I bought the Jethro Tull Christmas Album; even though not all the songs were new, they were new recordings and man, say what you want about Ian Anderson, the man knows how to record acoustic instruments.
Incidentially, Ian seems to have knicked a little credit: the song Birthday Card At Christmas, credited to Mr. Anderson, shares a melody with "I Believe In Father Christmas", the Greg Lake/ELP song, which was written by Lake and Peter Sinfield, which itself interpolated melodies from Prokofiev's Troika (I think it was Troika).