Complex sentence: Throughout the books, Aubrey is presented as interested in mathematics and astronomy, a great lover of music and player of the violin; he is a hearty singer and is generally accompanied by his friend and shipmate Stephen Maturin on the cello.
Split into simpler sentences: Throughout the books, Aubrey is presented as interested in mathematics and astronomy, a great lover of music and player of the violin; he is a hearty singer. On board ship, Aubrey on his violin is generally accompanied by his friend and shipmate Stephen Maturin on the cello.