This response is 7 years late but what the heck!

Fourum were indeed teachers from Hummersnott Comprehensive School in Darlington, County Durham, England.

Originally formed as a kind of PTA activity they still perform today although one or two have now retired from teaching. They still raise money for the school as far as I know and have released several albums.

The line-up was: Jim Jack (Guitar, Vocals, Business Studies & Latterly Headmaster of Richmond School), Bob Hattersley (drum, tamorine, vocals, wise-cracks & Geography), Alan ?(Guitar, Vocals, Lyricist & Latin), Sandy Still (Banjo?, Guitar, Vocals & English).

One or two other teachers came & went over the years.

Long may they continue.