Complex sentence: In 1988 KBIG began mixing in more rock and roll oldies from 1964 to 1969 as well as hotter AC artists, although, was still Gold Based AC at that point.
Split into simpler sentences: In 1988 KBIG began mixing in more rock and roll oldies from 1964 to 1969 as well as hotter AC artists. They were still Gold Based AC at that point.