Dominant Function: Dominant function refers to the role of a musical element in creating tension and leading back to the tonic (home base) within a piece of music.
Subdominant Function: Subdominant function refers to the role of a musical element in preparing for and transitioning between the dominant and tonic chords within a piece of music.
Modulation: Modulation occurs when there is a key change within a piece of music. It involves shifting from one tonal center (key) to another, often through specific harmonic progressions or melodic patterns.