Complex sentence: He became known as the nations first "on air" radio mix DJ. Heremixed and edited songs as a radio-mix DJ for the station, and these mixes became popular in the Miami area.
Split into simpler sentences: He became known as one of the nations first "on air" radio mix DJs. Rosenbergremixed and edited songs as a radio-mix DJ for the station, and these mixes became popular in the Miami area.