Complex sentence: Middle-entries tend to occur at pitches other than the initial--as shown in the typical structure above, these are often closely related keys such as the relative dominant and subdominant, but key structure of fugues varies greatly.
Split into simpler sentences: Middle-entries tend to occur at pitches other than the initial. As shown in the typical structure above, these are often closely related keys such as the relative dominant and subdominant, although the key structure of fugues varies greatly.