The cor anglais (also known as the English horn) primarily uses the treble clef for its notation.

Key Points:

1. Transposing Instrument:
   • The cor anglais is a transposing instrument in F, meaning that its written notes sound a perfect fifth lower than written.
   • For example, if a C is written, it sounds as an F below.
2. Occasional Bass Clef:
   • In rare cases, when the music descends into very low registers, the bass clef may be used, but this is uncommon.

Thus, most music for the cor anglais is written in the treble clef, accommodating its range and transposition.