I have a union query for two unrelated tables:
SELECT PairID, "Pair" AS [Relationship],StudentID,AcademicYr
FROM tblPairAssignment
GROUP BY PairID, StudentID, AcademicYr
ORDER BY StudentID
UNION SELECT AssignmentID, "Class" AS [Relationship], StudentID, AcademicYr
FROM tblClassAssignment
GROUP...