Despite these revelations, Wednesday's production of Joseph and the Amazing Technicolor Dreamcoat was a hit with the audience, which largely comprised of zealous parents, wrigg-ling pupils and an assort-ment of important school types - governors, senior managers and interview candidates.
I even think I saw the local vicar nodding in the back row. It's hard to remember. By that time, the potent mix of nervous tension and exhaustion had brought me to near hysteria.
What a show it was. Singing, dancing, dramatic climaxes, and some fine comic timing, to boot. Even the technology worked and since I seem to have a jinx effect on ICT rooms (hard drives have been known to melt), this was joyful. The technology involved pre-recorded video clips of our singing efforts, played to great effect on a giant screen above the stage - a sort of Andrew Lloyd Webber karaoke. I'm sure he would have been proud. It certainly provided a solution to the nagging fear that during the live performance, the piano chords would start and then be accompanied by...
Those who have heard my piano playing would probably agree it is at its best when drowned out by loud vocals.
After the show came a wave of euphoria, followed by a deep and quite fathomless tiredness unlike any I have ever known.
Nevertheless, once the half-chewed song sheets had been cleared away, I managed to muster the energy to join colleagues for a post-performance drink. And, of course, we all wanted to talk about the next one. I think we're ready for something braver. Chekhov anyone?
Louisa Leaman is a London teacher