By Katherine Sellgren
BBC News education and family reporter
Mr Walker says lessons must not be disrupted for the well-behaved
Detentions where pupils are forced to listen to classical music are an effective deterrent against unruly behaviour, a head teacher has found.
Brian Walker, head at West Park School in Derby, runs the two-hour detentions, featuring Elgar, Mozart, Verdi and Bach, on a Friday after school.
Pupils on their third official warning that week can expect to attend.
As well as listening to classical music for an hour, pupils also have to watch an educational television show.
For example, they have watched the Story of Maths, programmes from the National Geographic Channel, Chinese School and the World's Strictest Parents.
The detention has an average weekly attendance of 20 out of a total of 1,320 pupils.
The detentions are meted out as part of a specific formula for behaviour at the school.
The first warning - known as a C1 or Consequence 1 - sees a disruptive pupil receive a special warning from a teacher.
If they misbehave again, pupils are given a C2, which constitutes writing out the poem, Jerusalem - Mr Walker's favourite.
A C3 sees pupils told off by the head and an automatic two-hour Friday detention.
Mr Walker says his main aim is to stop disruptive pupils spoiling lessons for the well-behaved majority.
"These are the disrupters of learning, not the smokers, the truants or the people who are late - they are dealt with through other procedures.
"It's those who have slowed the learning process in class for everyone and I won't have that, because it is robbing the rest of opportunities."
Mr Walker says the detention serves as a positive reminder that an education is something to value.
"It helps them see they are part of something bigger that will enhance their life chances if they become a net contributor, rather than detracting from it.
"When it's finished, there's no anger or resentment, because it's not a punishment, but pointing out the consequences of their behaviour.
"Hopefully, I open their ears to an experience they don't normally have and it seems many of them don't want to have it again, so it's both educational and acts as a deterrent."