Lesson 20. The Banshee (McMahon’s) The Banshee is a reel that's sometimes know as McMahon's. The first part is in G Major; it changes to E Minor in the second part. The last two bars in the first and second parts are identical, which will help in learning. PlayPause Gerry GaffneyLesson 20. The Banshee (McMahon’s)01.19.2008