[Some song titles in this thread have been converted to links by a Mudelf.] On another thread in another place, someone remarked that the only traditional Halloween song they could find was "Soul Cake" (as recorded by the Watersons on "Frost and Fire"). It seems to me at a guess that that might more accurately be called an All Soul's Day song.
Of course, Tam Lin and the various versions of Child 39 do spring to mind as referring to Halloween - but a short rummage has failed to turn up the expected plethora of traditional (by which I mean traditional, OK) songs about or for Samhain/Halloween.
What else does the team know?