Question

What kind of harmony uses only notes from the key signature

Answer 1

Music consists of three main elements—melody, rhythm, and harmony. While the first two are typically accountable for making a piece of music memorable—think of the opening motif of Beethoven’s Symphony No. 5, or Timbaland’s synth lick on the Jay-Z song “Dirt Off Your Shoulder”—it’s the third element, harmony, that can elevate a piece from common and predictable to challenging and sophisticated.

Answer 2

In the key of C, the root note is C, the major third is E, and the dominant note (or the ... we can use a note within a 3rd of that note in order to create a harmony that ... your goal is to bolster the melody and not compete with it you will be just fine.