Thank you for your prompt reply, I am against the wall on this one!
The criteria for this field is set as
the [Class] is from a combo box.
SQL look slike this
SELECT T_Graduate.PersonalID, T_Graduate.CellCohort, T_Graduate.Forename, T_Graduate.Surname
FROM (T_Graduate LEFT JOIN T_Attendance ON T_Graduate.PersonalID = T_Attendance.personal_id) LEFT JOIN T_Attendance_notes ON T_Attendance.attendanceid = T_Attendance_notes.attendanceid
ORDER BY T_Graduate.CellCohort, T_Graduate.Surname;