Complex sentence: There are many different types of concertinas, which is how the Boer music has so many different unique sounds and styles, and the construction the concertina is what makes the different sounds in the Boer music band.
Split into simpler sentences: There are many different types of concertinas which is how the Boer music has so many different unique sounds and styles. The construction the concertina is what makes the different sounds in the Boer music band.