Complex sentence: It was their eighth studio release and the last REO album to prominently feature a more hard rock sound, and was in fact their hardest rocking release, after which the band would turn to more pop-oriented material with 1980's Hi Infidelity.
Split into simpler sentences: It was their eighth studio release and the last REO album to prominently feature a more hard rock sound. The band would turn to more pop-oriented material with 1980's Hi Infidelity.