Answer:
In tonal music, chord progressions have the function of establishing or contradicting a tonality, the technical name for what is commonly understood as the "key" of a song or piece. Chord progressions are usually expressed by Roman numerals in Classical music theory. For example, the common chord progression I–vi–ii–V.
Explanation:
D. New Orleans
explanation because
It depends if it's a single or a double bar line.
if it's a double bar line it's just there to separate the sections of the music and if it's a single bar line all it does it separate the beats in order to make a measure.
