The cor anglais ( /ˌkɔr ˈɑːŋɡleɪ/ or /ˌkɔr ɒŋˈɡleɪ/; ), or English horn (American English), is a double-reed woodwind instrument in the oboe family.
The cor anglais is a transposing instrument pitched in F, a perfect fifth lower than the oboe (a C instrument), and is consequently approximately one and a half times the length of the oboe. The fingering and playing technique used for the cor anglais are essentially the same as those of the oboe, and most oboists double on the cor anglais. Music for the cor anglais is thus written a perfect fifth higher than the instrument actually sounds. Because the cor anglais normally lacks the lowest B-flat of the oboe, its sounding range stretches from the E (written B natural) below middle C to the C two octaves above middle C.
Read more about Cor Anglais: Description and Timbre, History and Etymology, Use Outside Classical Music