Complex sentence: Buddy's films weren't much different from Bosko's; as in Bosko's shorts, music also dominates in Buddy's world, and the characters merely exist to add a visual to the soundtrack and to participate in the odd gag.
Split into simpler sentences: Buddy's films weren't much different from Bosko's, either. Music dominates in Buddy's world, and the characters merely exist to add a visual to the soundtrack and to participate in the odd gag.