educate me please re: major/minor parallel keys
So here is something on which I am not clear, among about a bazillion other things. In some ITM tunes, the key will change from the A part to the B part, from a major scale to its parallel minor, or vice versa. The Connaughtman’s Rambles is a good example of this, "changing" from D major to B minor.
As a fiddler, this fact is of no value to me, at least that I know of, because both keys have an F# and a C#. Both keys have all the same notes. What is the point of the key change? Is it more for backing musicians, to help with appropriate chords?