Zu is newly sober when she receives news that she is to become the sole guardian of her half-sister named Music, a young girl on the autism spectrum. The film explores two of Sia's favorite ... Read allZu is newly sober when she receives news that she is to become the sole guardian of her half-sister named Music, a young girl on the autism spectrum. The film explores two of Sia's favorite themes: finding your voice and creating family.Zu is newly sober when she receives news that she is to become the sole guardian of her half-sister named Music, a young girl on the autism spectrum. The film explores two of Sia's favorite themes: finding your voice and creating family.