Specialist subjects are taught by specialists in their field:

It is far better to receive information or instruction from a person who has particular knowledge, understanding and experience, even passion, about a particular field than from one who just "dabbles" or knows and understands only what is needed. It is for this reason that we believe specialist subjects such as Music, French or Sport etc. should be taught by a specialist teacher, much as they would be at Secondary School or University. Core subjects such as English, Maths, History and Geography are taught by highly competent Form Tutors.