Complex sentence: At the age of 19, while working as a field hand, he began to perform professionally, mostly at local parties and picnics, with the accompaniment of Hammie Nixon, a harmonica player, and James "Yank" Rachell, a guitarist and mandolin player.
Split into simpler sentences: At the age of 19, while working as a field hand, he began to perform professionally. The venues were mostly local parties and picnics, with the accompaniment of Hammie Nixon, a harmonica player, and James "Yank" Rachell, a guitarist and mandolin player.