Complex sentence: He became friends with Albert Ammons during childhood, a friendship that would last throughout their lives, they went to the same school together briefly, and they practiced and learned the piano together on the Ammons family piano.
Split into simpler sentences: He became friends with Albert Ammons during childhood, a friendship that would last throughout their lives. They went to the same school together briefly and they practiced and learned the piano together on the Ammons family piano.