In this post I’ll discuss the music theory behind a particular key change. The song “Wrestle the Reticence” is in G major, but at the end, there is a key change into the key of A major. However, this transition needed to happen naturally and smoothly so the listener isn’t shocked by the change and actually feels as though the change was necessary.
The trumpet leads the key change by bringing the melodic line from the root (G) to the fifth (D) and then to the 2nd of the G major scale, which is A. Going into the key change, the melodic line is sitting on the 2nd degree of the original scale, G major. This naturally wants to resolve down to the first scale degree, or the root, which is G. However instead of bringing the melody back down the scale root, I brought the scale root up to the melody, thus completing the key change and giving the melody a resolved feeling because now the A that is being played is no longer functioning as the 2nd degree of G major, but the root of A major.
