An upper structure triad is made up of three notes that are played at the same time. These three notes come from two different chords that are stacked on top of each other. It's like building a tower out of blocks! The bottom chord is called the "root chord" and the top chord is called the "upper structure". It's like putting a hat on top of the tower!
The root chord gives us our basic foundation and the upper structure gives us some extra flavor. By combining these two chords, we get a really interesting sound. This is because the upper structure adds some new notes that are different from the ones we normally hear in the root chord.
Overall, an upper structure triad is like playing two chords at once to create a unique and complex sound that can add a lot of depth and emotion to music.