Lesson 40. Caisleán an Óir Caisleán an Óir is a hornpipe. This arrangement is in D Dorian, a type of D Minor, but without a Bb in the key signature. The D Dorian has the same notes as the C Major Scale. PlayPause Gerry GaffneyLesson 40. Caisleán an Óir03.14.2009