Who was the first to propose the heliocentric system? A. Aristotle B. Copernicus C. Ptolemy D. Aristarchus

Copernicus was the first to propose a heliocentric system

It depends on what type of third separates the three notes.for example: if you have two mayor thirds is an "aumented chord"if you have two minor thirds is an "diminued chord"if you have one mayor first and then one minor is a "mayor chord"and inverted is a "minor chord"