It is set in Barnsley, South Yorkshire and tells of Billy Casper, a young working class boy troubled at home and at school, who only finds solace when he finds and trains a kestrel whom he names "Kes".
Other productions include Caged, Pobby and Dingan (TMA 2010 award winner for Best Show for Children and Young People), The Book of Beasts, Something Wicked This Way Comes (with National Theatre of Scotland), The Ballad of Pondlife McGurk, Hansel and Gretel, Kes, The Lion of Kabul, The Book of Beasts, Cyrano, Snow Baby, and The Story of the Little Gentleman.
In Star Trek: Voyager, the Doctor often compliments himself on the charming bedside manner he developed with the help of Kes.
The video to the band's "Blue Note" single was based on the film Kes, and starred Phoenix Nights star Steve Edge as a Brian Glover-style PE teacher.
KES, named after the reigning monarch, was formed in 1905 when Wesley College was merged with Sheffield Royal Grammar School (SRGS) on the site of the former on Glossop Road.
The first line opened on 24 November 1899 when they opened their tracks from Sagene to Aker Street (the Sagene Ring), connecting onwards to the Eastern Railway Station (Østbanen) using KES tracks.
From 1905 to 1926, Kes was director of a music conservatory in Koblenz.