Complex sentence: Darnell began his musical career in a band named The In-Laws with his brother, Stony Browder Jr, in 1965, which disbanded so Darnell could pursue a career as an English teacher.
Split into simpler sentences: Darnell began his musical career in a band named The In-Laws with his brother, Stony Browder Jr., in 1965. The band disbanded so Darnell could pursue a career as an English teacher.