In 2007, choirmaster Gareth Malone took a teaching position at one of the largest all-boys comprehensives in the country. He wanted to prove that singing could be a positive and enjoyable activity for boys. When Gareth arrived at the school, singing was a dirty word, but over two terms Gareth battled entrenched attitudes, building up a 100-strong choir from nothing, until they were good enough to perform at the Royal Albert Hall. Now, exactly one year after he left, Gareth is returning to the school to catch up with his former choir members and see if his time there had any permanent impact.