Primary Muscles: latissimus dorsi
Secondary Muscles: posterior deltoids, biceps, brachialis, trapezius, levator scapulae, rhomboids
Changing the angle of a row will allow your body to use various muscles of the back and shoulder, there are an insane amount! Utilizing this angle allows for more upper back muscles activation such as the Levator Scapulae which is less engaged in a normal row.