Complex sentence: There are seven pedals, each affecting the tuning of all strings of one pitch-class, and each pedal is attached to a rod or cable within the column of the harp, which then connects with a mechanism within the neck.
Split into simpler sentences: There are seven pedals, each affecting the tuning of all strings of one pitch-class. Each pedal is attached to a rod or cable within the column of the harp, which then connects with a mechanism within the neck.