"Poignant" was their description of a lunchtime club at the special school, where pupils give up their free time to sing and sign along with passion to their favourite songs.
"The mood veers between a rock concert and a spiritual gathering. As each track finishes, students hug, clap and hold each other. They leave with their confidence soaring; uplifted and exhilarated," the inspectors said.
That performance, among much else, moved inspectors to name the school among this year's examples of outstanding practice.
The school where nearly half of the 110 pupils are eligible for free school meals, answers the chief inspector's criticism that social class too often determines pupils' futures.
"We don't see the disadvantages, what we see is huge potential. We don't hold back our ambitions for these children at all," Linda Jones, acting headteacher, said.
Inspectors said they achieved exceptional results for students with a high rate of complex special needs.
At the heart of their success was an overhaul of the curriculum, which is divided into three strands of sensory, supported and independent learning.
The inspectors said one science lesson examining air resistance acting on trucks fitted with sails, which left pupils clamouring for more, was inspirational.
Mrs Jones takes a few minutes to stop laughing when asked if staff work long hours.
She resumes, diplomatically: "We are a very dedicated and committed team, I think you could say."