FYI & FWIW,
Michael Jackson has songwriting credit for four of the nine tracks on Thriller. QJ shares songwriting credit on just one.
Michael Jackson: Arranger, Composer, Drums, Guitar, Handclapping, Horn Arrangements, Producer, Rhythm Arrangements, Sound Effects, Stomp Board, Synthesizer Arrangements, Vocal Arrangement, Vocals, Vocals (Background)
Quincy Jones: Arranger, Producer, Rhythm Arrangements, Vocal Arrangement