Complex sentence: During the station's early days the playlist featured music from mostly the 1950s and 1960s, music from the 1950s was dropped in the early 2000s with the stations emphasis on 1960s and 1970s music for most of the decade.
Split into simpler sentences: During the station's early days the playlist featured mostly music from the 1950s and 1960s. Music from the 1950s was dropped in the early 2000s, with the station focusing on 1960s and 1970s music for most of the decade.