Two of my middle and high school orchestra director's sons played in his orchestra at different times. I always thought it was unfair to them that, by Mr. D.'s own admission, "I grade them harder than I grade the rest of you."
I saw that double standard in action one day when one of his sons finished a playing test. I expected Mr. D. to mark down an A in the grade book, as his playing sounded just as good as the student before him, who received an A. Instead, however, Mr. D.'s son received a B+. His reasoning is being tougher on his sons was that they had him available as a resource at home while the rest of us didn't.
I suppose there's a case to be made for that. The stronger case, however, would be, "If a student plays well enough to earn an A, that student should receive an A."
