In a music competition, an earnest and likeable person gets up and performs a song which he or she loves and has worked on for months. She nods to the pianist and smiles nervously at the adjudicator while her supporters gaze up, fingers crossed, willing her to succeed.

The moment she utters the first note, your heart sinks. She is, frankly, not up to it. The tuning’s ropey, the words are indistinct and the emotional message of the song isn’t there. So you write some comments on her sheet and add a mark, and then - the real test - you stand up to say something sensible to her in front of her friends and family. “Blah di blah, sincere, bold attempt, correct tempo...”

You pause, and look over your glasses to where the singer sits with her supporters.

“However...” (another pause, with a smile), “here are a few things that I really hope you will bear in mind.”

At that moment you cease to be a judge and become a teacher. There’s no evading your duty to get across, unambiguously, the fact that today’s effort wasn’t good enough. But the trick, for which you are being paid, is to do it so positively and professionally that the singer comes to thank you at the end and ask for a few more pointers.

The whole encounter doesn’t last more than 15 minutes, but isn’t it actually a fair model of a good lesson observation? Or any of the mentoring activities that go with leadership? In school, the details are different, the protocols are tight, the framework is professionally defined, and the feedback is not given in public. Like the adjudicator, though, we are surely striving to provide assessments that are honest but come packaged with realistic ideas for improvement. Or is that pie in the sky? Let me know.