Many traditional tunes are in minor keys, or, more correctly, they are modal in structure. The four most common modes found in Irish music are the Ionian mode which we now know as the major scale and, the Aeolian, Dorian, and Mixolydian modes which are what traditional musicians are referring to when they talk about minor keys. The main difference between the Aeolian mode and the Classical minor key is that the minor key has a sharpened seventh but the Aeolian doesn’t. For now it should suffice to know that when a tune is said to be in a minor key (usually a, e, g, and d minor) you should flatten the third and the seventh of the scale. This is what the minor scale most often used in traditional music sounds like. Notice the C natural on third fret, and the G natural on the third fret of the A & E strings respectively.